485BPOS

Securities Act of 1933 Registration No. 002-69972

Investment Company Act of 1940 Registration No. 811-03114

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 x

o Pre-Effective Amendment No.  ______

x Post-Effective Amendment No.  _144_

and

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940 x

x Amendment No.  _144_

Fidelity Select Portfolios

 (Exact Name of Registrant as Specified in Charter)

245 Summer Street, Boston, Massachusetts 02210

(Address of Principal Executive Offices)(Zip Code)

Registrant’s Telephone Number: 617-563-7000

William C. Coffey, Secretary

245 Summer Street

Boston, Massachusetts 02210

(Name and Address of Agent for Service)

It is proposed that this filing will become effective immediately upon filing pursuant to paragraph (b) of Rule 485.

EXHIBIT INDEX

Exhibit	Exhibit No.
XBRL Instance Document	EX-101.INS
XBRL Taxonomy Extension Schema Document	EX-101.SCH
XBRL Taxonomy Extension Calculation Linkbase Document	EX-101.CAL
XBRL Taxonomy Extension Definition Linkbase Document	EX-101.DEF
XBRL Taxonomy Extension Labels Linkbase Document	EX-101.LAB
XBRL Taxonomy Extension Presentation Linkbase Document	EX-101.PRE

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for the effectiveness of this Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Post-Effective Amendment No. 144 to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Boston, and Commonwealth of Massachusetts, on the 17th day of October 2018.

	Fidelity Select Portfolios
	By	/s/Stacie M. Smith
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||		Stacie M. Smith, President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

(Signature)		(Title)	(Date)
/s/Stacie M. Smith		President and Treasurer	October 17, 2018
Stacie M. Smith		(Principal Executive Officer)
/s/John J. Burke III		Chief Financial Officer	October 17, 2018
John J. Burke III		(Principal Financial Officer)
/s/James C. Curvey	*	Trustee	October 17, 2018
James C. Curvey
/s/Dennis J. Dirks	*	Trustee	October 17, 2018
Dennis J. Dirks
/s/Donald F. Donahue	*	Trustee	October 17, 2018
Donald F. Donahue
/s/Alan J. Lacy	*	Trustee	October 17, 2018
Alan J. Lacy
/s/Ned C. Lautenbach	*	Trustee	October 17, 2018
Ned C. Lautenbach
/s/Joseph Mauriello	*	Trustee	October 17, 2018
Joseph Mauriello
/s/Charles S. Morrison	*	Trustee	October 17, 2018
Charles S. Morrison
/s/Cornelia M. Small	*	Trustee	October 17, 2018
Cornelia M. Small
/s/Garnett A. Smith	*	Trustee	October 17, 2018
Garnett A. Smith
/s/David M. Thomas	*	Trustee	October 17, 2018
David M. Thomas
/s/Michael E. Wiley	*	Trustee	October 17, 2018
Michael E. Wiley

*	By:	/s/Megan C. Johnson
		Megan C. Johnson, pursuant to powers of attorney dated March 2, 2018 and filed herewith.

POWER OF ATTORNEY

We, the undersigned Directors or Trustees, as the case may be, of the following investment companies:

Fidelity Advisor Series I Fidelity Advisor Series VII Fidelity Advisor Series VIII Fidelity Beacon Street Trust Fidelity Capital Trust Fidelity Central Investment Portfolios LLC Fidelity Commonwealth Trust Fidelity Commonwealth Trust II Fidelity Concord Street Trust Fidelity Congress Street Fund Fidelity Contrafund Fidelity Covington Trust Fidelity Destiny Portfolios Fidelity Devonshire Trust Fidelity Exchange Fund Fidelity Financial Trust Fidelity Hanover Street Trust Fidelity Hastings Street Trust Fidelity Investment Trust Fidelity Magellan Fund Fidelity Mt. Vernon Street Trust Fidelity Puritan Trust Fidelity Securities Fund Fidelity Select Portfolios Fidelity Summer Street Trust Fidelity Trend Fund Variable Insurance Products Fund Variable Insurance Products Fund II Variable Insurance Products Fund III Variable Insurance Products Fund IV

in addition to any other investment company for which Fidelity Management & Research Company (“FMR”) or an affiliate acts as investment adviser and for which the undersigned individuals serve as Directors or Trustees (collectively, the “Funds”), hereby revoke all previous powers of attorney we have given to sign and otherwise act in our names and behalf in matters involving any investment company for which FMR or an affiliate acts as investment adviser and hereby constitute and appoint Thomas C. Bogle, John V. O’Hanlon, Robert W. Helm, Megan C. Johnson, and Anthony H. Zacharski, each of them singly, our true and lawful attorneys-in-fact, with full power of substitution, and with full power to each of them, to sign for us and in our names in the appropriate capacities, all Registration Statements of the Funds on Form N-1A, or any successors thereto, any and all subsequent Amendments, Pre-Effective Amendments, or Post-Effective Amendments to said Registration Statements or any successors thereto, and any supplements or other instruments in connection therewith, and generally to do all such things in our names and behalf in connection therewith as said attorneys–in-fact deem necessary or appropriate, to comply with the provisions of the Securities Act of 1933 and the Investment Company Act of 1940, and all related requirements of the Securities and Exchange Commission.  We hereby ratify and confirm all that said attorneys-in-fact or their substitutes may do or cause to be done by virtue hereof.  This power of attorney is effective for all documents filed on or after March 2, 2018.

WITNESS our hands on this second day of March 2018.

/s/ James C. Curvey	/s/ Joseph Mauriello
James C. Curvey	Joseph Mauriello
/s/ Dennis J. Dirks	/s/ Charles S. Morrison
Dennis J. Dirks	Charles S. Morrison
/s/ Donald F. Donahue	/s/ Cornelia M. Small
Donald F. Donahue	Cornelia M. Small
/s/ Alan J. Lacy	/s/ Garnett A. Smith
Alan J. Lacy	Garnett A. Smith
/s/ Ned C. Lautenbach	/s/ David M. Thomas
Ned C. Lautenbach	David M. Thomas

POWER OF ATTORNEY

I, the undersigned Director or Trustee, as the case may be, of the following investment companies:

Fidelity Advisor Series I Fidelity Advisor Series VII Fidelity Beacon Street Trust Fidelity Capital Trust Fidelity Central Investment Portfolios LLC Fidelity Commonwealth Trust Fidelity Commonwealth Trust II Fidelity Congress Street Fund Fidelity Contrafund Fidelity Covington Trust Fidelity Destiny Portfolios Fidelity Devonshire Trust Fidelity Exchange Fund Fidelity Financial Trust Fidelity Hanover Street Trust Fidelity Hastings Street Trust Fidelity Magellan Fund Fidelity Mt. Vernon Street Trust Fidelity Select Portfolios Fidelity Summer Street Trust Fidelity Trend Fund Variable Insurance Products Fund II Variable Insurance Products Fund III Variable Insurance Products Fund IV

in addition to any other investment company for which Fidelity Management & Research Company (“FMR”) or an affiliate acts as investment adviser and for which the undersigned individual serves as Director or Trustee (collectively, the “Funds”), hereby revokes all previous powers of attorney I have given to sign and otherwise act in my name and behalf in matters involving any investment company for which FMR or an affiliate acts as investment adviser and hereby constitute and appoint Thomas C. Bogle, John V. O’Hanlon, Robert W. Helm, Megan C. Johnson, and Anthony H. Zacharski, each of them singly, my true and lawful attorneys-in-fact, with full power of substitution, and with full power to each of them, to sign for me and in my name in the appropriate capacities, all Registration Statements of the Funds on Form N-1A, or any successors thereto, any and all subsequent Amendments, Pre-Effective Amendments, or Post-Effective Amendments to said Registration Statements or any successors thereto, and any supplements or other instruments in connection therewith, and generally to do all such things in my name and behalf in connection therewith as said attorneys–in-fact deem necessary or appropriate, to comply with the provisions of the Securities Act of 1933 and the Investment Company Act of 1940, and all related requirements of the Securities and Exchange Commission.  I hereby ratify and confirm all that said attorneys-in-fact or their substitutes may do or cause to be done by virtue hereof.  This power of attorney is effective for all documents filed on or after March 2, 2018.

WITNESS our hands on this second day of March 2018.

/s/ Michael E. Wiley    

Michael E. Wiley

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Sep. 28, 2018
Registrant Name	dei_EntityRegistrantName	FIDELITY SELECT PORTFOLIOS
Central Index Key	dei_EntityCentralIndexKey	0000320351
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Sep. 28, 2018
Document Effective Date	dei_DocumentEffectiveDate	Sep. 29, 2018
Prospectus Date	rr_ProspectusDate	Sep. 29, 2018

XML

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Consumer Staples Portfolio</b>/Fidelity Advisor® Consumer Staples Fund Z</p>

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

The fund seeks capital appreciation.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

Shareholder Fees {- Consumer Staples Portfolio}	NF_FA Consumer Staples Fund_Class Z PRO-01 Consumer Staples Portfolio USD ($)
(fees paid directly from your investment)	none

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Annual Operating Expenses {- Consumer Staples Portfolio}	NF_FA Consumer Staples Fund_Class Z PRO-01 Consumer Staples Portfolio Fidelity Advisor Consumer Staples Fund: Class Z
Management fee	0.54%
Distribution and/or Service (12b-1) fees	none
Other expenses	0.10%	[1]
Total annual operating expenses	0.64%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Expense Example {- Consumer Staples Portfolio}	NF_FA Consumer Staples Fund_Class Z PRO-01 Consumer Staples Portfolio Fidelity Advisor Consumer Staples Fund: Class Z USD ($)
1 year	$ 65
3 years	205
5 years	357
10 years	$ 798

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 76% of the average value of its portfolio.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, sale, or distribution of consumer staples.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Consumer Staples Industry Concentration. The consumer staples industries can be significantly affected by demographics and product trends, competitive pricing, food fads, marketing campaigns, environmental factors, government regulation, the performance of the overall economy, interest rates, consumer confidence, and the cost of commodities.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	14.49%	June 30, 2009
Lowest Quarter Return	-12.95%	December 31, 2008
Year-to-Date Return	-8.98%	June 30, 2018

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

Average Annual Total Returns{- Consumer Staples Portfolio} - NF_FA Consumer Staples Fund_Class Z PRO-01 - Consumer Staples Portfolio	Past 1 year	Past 5 years	Past 10 years
Fidelity Advisor Consumer Staples Fund: Class I | Return Before Taxes	12.06%	10.45%	8.37%
Fidelity Advisor Consumer Staples Fund: Class I | After Taxes on Distributions	9.86%	8.65%	7.29%
Fidelity Advisor Consumer Staples Fund: Class I | After Taxes on Distributions and Sales	8.61%	8.10%	6.73%
S&P 500® Index(reflects no deduction for fees, expenses, or taxes)	21.83%	15.79%	8.50%
MSCI U.S. IMI Consumer Staples 25-50 Index(reflects no deduction for fees, expenses, or taxes)	11.91%	13.42%	10.16%

[1] Based on estimated amounts for the current fiscal year.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY SELECT PORTFOLIOS

Prospectus Date

rr_ProspectusDate

Sep. 29, 2018

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Consumer Staples Portfolio</b>/Fidelity Advisor® Consumer Staples Fund Z</p>

Objective [Heading]

rr_ObjectiveHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

(fees paid directly from your investment)

rr_ShareholderFeeOther

none

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 76% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

76.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

<font style="FONT-FAMILY: Times New Roman" size="3">Based on estimated amounts for the current fiscal year.</font>

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Strategy [Heading]

rr_StrategyHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, sale, or distribution of consumer staples.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

<font style="FONT-FAMILY: Times New Roman" size="3">Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, sale, or distribution of consumer staples.</font>

Risk [Heading]

rr_RiskHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Consumer Staples Industry Concentration. The consumer staples industries can be significantly affected by demographics and product trends, competitive pricing, food fads, marketing campaigns, environmental factors, government regulation, the performance of the overall economy, interest rates, consumer confidence, and the cost of commodities.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

Risk Lose Money [Text]

rr_RiskLoseMoney

<font style="FONT-FAMILY: Times New Roman" size="3">You could lose money by investing in the fund.</font>

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

<font style="FONT-FAMILY: Times New Roman" size="3">In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.</font>

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

<font style="FONT-FAMILY: Times New Roman" size="3">An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</font>

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

<font style="FONT-FAMILY: Times New Roman" size="3">The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time.</font>

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

<font style="FONT-FAMILY: Times New Roman" size="3">institutional.fidelity.com </font>

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

<font style="FONT-FAMILY: Times New Roman" size="3">Past performance (before and after taxes) is not an indication of future performance.</font>

Bar Chart [Heading]

rr_BarChartHeading

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	14.49%	June 30, 2009
Lowest Quarter Return	-12.95%	December 31, 2008
Year-to-Date Return	-8.98%	June 30, 2018

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

<font style="FONT-FAMILY: Times New Roman" size="3">* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.</font>

Performance Table Heading

rr_PerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

<font style="FONT-FAMILY: Times New Roman" size="3">After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.</font>

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

<font style="FONT-FAMILY: Times New Roman" size="3">The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).</font>

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | Fidelity Advisor Consumer Staples Fund: Class Z

Risk/Return:

rr_RiskReturnAbstract

Management fee

rr_ManagementFeesOverAssets

0.54%

Distribution and/or Service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.10%

^[1]

Total annual operating expenses

rr_ExpensesOverAssets

0.64%

1 year

rr_ExpenseExampleYear01

$ 65

3 years

rr_ExpenseExampleYear03

205

5 years

rr_ExpenseExampleYear05

357

10 years

rr_ExpenseExampleYear10

$ 798

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | Fidelity Advisor Consumer Staples Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(22.29%)

2009

rr_AnnualReturn2009

20.99%

2010

rr_AnnualReturn2010

15.22%

2011

rr_AnnualReturn2011

8.79%

2012

rr_AnnualReturn2012

15.35%

2013

rr_AnnualReturn2013

21.59%

2014

rr_AnnualReturn2014

14.89%

2015

rr_AnnualReturn2015

1.90%

2016

rr_AnnualReturn2016

3.04%

2017

rr_AnnualReturn2017

12.06%

Year to Date Return, Label

rr_YearToDateReturnLabel

Year-to-Date Return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2018

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

(8.98%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarter Return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

14.49%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarter Return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(12.95%)

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | Return Before Taxes | Fidelity Advisor Consumer Staples Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Consumer Staples Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return Before Taxes</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

12.06%

Past 5 years

rr_AverageAnnualReturnYear05

10.45%

Past 10 years

rr_AverageAnnualReturnYear10

8.37%

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | After Taxes on Distributions | Fidelity Advisor Consumer Staples Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Consumer Staples Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

9.86%

Past 5 years

rr_AverageAnnualReturnYear05

8.65%

Past 10 years

rr_AverageAnnualReturnYear10

7.29%

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | After Taxes on Distributions and Sales | Fidelity Advisor Consumer Staples Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Consumer Staples Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions and Sale of Fund Shares</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

8.61%

Past 5 years

rr_AverageAnnualReturnYear05

8.10%

Past 10 years

rr_AverageAnnualReturnYear10

6.73%

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | S&P 500® Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

21.83%

Past 5 years

rr_AverageAnnualReturnYear05

15.79%

Past 10 years

rr_AverageAnnualReturnYear10

8.50%

NF_FA Consumer Staples Fund_Class Z PRO-01 | Consumer Staples Portfolio | MSCI U.S. IMI Consumer Staples 25-50 Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

11.91%

Past 5 years

rr_AverageAnnualReturnYear05

13.42%

Past 10 years

rr_AverageAnnualReturnYear10

10.16%

[1] Based on estimated amounts for the current fiscal year.

XML

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Gold Portfolio</b>/Fidelity Advisor® Gold Fund Z</p>

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

The fund seeks capital appreciation.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

Shareholder Fees {- Gold Portfolio}	NF_FA Gold Fund_Class Z PRO-01 Gold Portfolio USD ($)
(fees paid directly from your investment)	none

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Annual Operating Expenses {- Gold Portfolio}	NF_FA Gold Fund_Class Z PRO-01 Gold Portfolio Fidelity Advisor Gold Fund: Class Z
Management fee	0.54%
Distribution and/or Service (12b-1) fees	none
Other expenses	0.13%	[1]
Acquired fund fees and expenses	0.03%	[2],[3]
Total annual operating expenses	0.70%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Expense Example {- Gold Portfolio}	NF_FA Gold Fund_Class Z PRO-01 Gold Portfolio Fidelity Advisor Gold Fund: Class Z USD ($)
1 year	$ 72
3 years	224
5 years	390
10 years	$ 871

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 13% of the average value of its portfolio.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

• Normally investing primarily in common stocks and in certain precious metals.

• Investing primarily in companies engaged in exploration, mining, processing, or dealing in gold, or to a lesser degree, in silver, platinum, diamonds, or other precious metals and minerals.

• Normally investing at least 80% of assets in securities of companies principally engaged in gold-related activities, and in gold bullion or coins.

• Investing up to 25% of assets in gold and other precious metals through a wholly-owned subsidiary organized under the laws of the Cayman Islands.

• Potentially investing in other precious metals, instruments whose value is linked to the price of precious metals, and securities of companies that manufacture and distribute precious metal and minerals products (such as jewelry, watches, and metal foil and leaf) and companies that invest in other companies engaged in gold and other precious metal and mineral-related activities.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile.

• Gold Industry Concentration. The gold industry can be significantly affected by international monetary and political developments such as currency devaluations or revaluations, central bank movements, economic and social conditions within a country, trade imbalances, or trade or currency restrictions between countries, as well as supply and demand for gold and operational costs associated with mining.

• Subsidiary Risk. Investment in an unregistered subsidiary is not subject to the investor protections of the Investment Company Act of 1940 (1940 Act) and is subject to the risks associated with the gold industry. Changes in tax and other laws could negatively affect investments in the subsidiary.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	41.01%	March 31, 2016
Lowest Quarter Return	-37.34%	June 30, 2013
Year-to-Date Return	-8.09%	June 30, 2018

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

Average Annual Total Returns{- Gold Portfolio} - NF_FA Gold Fund_Class Z PRO-01 - Gold Portfolio	Past 1 year	Past 5 years	Past 10 years
Fidelity Advisor Gold Fund: Class I | Return Before Taxes	8.58%	(10.17%)	(4.41%)
Fidelity Advisor Gold Fund: Class I | After Taxes on Distributions	8.50%	(10.44%)	(4.94%)
Fidelity Advisor Gold Fund: Class I | After Taxes on Distributions and Sales	4.88%	(7.42%)	(2.98%)
S&P 500® Index(reflects no deduction for fees, expenses, or taxes)	21.83%	15.79%	8.50%
S&P® Global BMI Gold Capped 20/45 Linked Index(reflects no deduction for fees, expenses, or taxes)	11.59%	(9.89%)	(4.79%)

[1] Based on estimated amounts for the current fiscal year.

[2] Based on historical expenses, adjusted to reflect current fees.

[3] The fund may invest in a wholly-owned subsidiary. The subsidiary has entered into a separate contract with Fidelity Management &amp; Research Company (FMR), an affiliate of Fidelity SelectCo, LLC (SelectCo), the fund's investment adviser, for the management of its portfolio pursuant to which the subsidiary pays FMR a fee at an annual rate of 0.30% of its net assets. The subsidiary also pays certain other expenses including custody fees. SelectCo has contractually agreed to waive the fund's management fee in an amount equal to the management fee paid to FMR by the subsidiary. This arrangement will remain in effect for at least one year from the effective date of the prospectus, and will remain in effect thereafter as long as FMR's contract with the subsidiary is in place, and neither SelectCo nor any of its affiliates retain the ability to be repaid with respect to this arrangement. If FMR's contract with the subsidiary is terminated, SelectCo, in its sole discretion, may discontinue the arrangement.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY SELECT PORTFOLIOS

Prospectus Date

rr_ProspectusDate

Sep. 29, 2018

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Gold Portfolio</b>/Fidelity Advisor® Gold Fund Z</p>

Objective [Heading]

rr_ObjectiveHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

(fees paid directly from your investment)

rr_ShareholderFeeOther

none

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

<font style="FONT-FAMILY: Times New Roman" size="3">remain in effect for at least one year from the effective date of the prospectus, and will remain in effect thereafter as long as FMR's contract with the subsidiary is in place, and neither SelectCo nor any of its affiliates retain the ability to be repaid with respect to this arrangement.</font>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 13% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

13.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

<font style="FONT-FAMILY: Times New Roman" size="3">Based on estimated amounts for the current fiscal year.</font>

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

<font style="FONT-FAMILY: Times New Roman" size="3">Based on historical expenses, adjusted to reflect current fees.</font>

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Strategy [Heading]

rr_StrategyHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

• Normally investing primarily in common stocks and in certain precious metals.

• Investing primarily in companies engaged in exploration, mining, processing, or dealing in gold, or to a lesser degree, in silver, platinum, diamonds, or other precious metals and minerals.

• Normally investing at least 80% of assets in securities of companies principally engaged in gold-related activities, and in gold bullion or coins.

• Investing up to 25% of assets in gold and other precious metals through a wholly-owned subsidiary organized under the laws of the Cayman Islands.

• Potentially investing in other precious metals, instruments whose value is linked to the price of precious metals, and securities of companies that manufacture and distribute precious metal and minerals products (such as jewelry, watches, and metal foil and leaf) and companies that invest in other companies engaged in gold and other precious metal and mineral-related activities.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

<font style="FONT-FAMILY: Times New Roman" size="3">Normally investing at least 80% of assets in securities of companies principally engaged in gold-related activities, and in gold bullion or coins.</font>

Risk [Heading]

rr_RiskHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile.

• Gold Industry Concentration. The gold industry can be significantly affected by international monetary and political developments such as currency devaluations or revaluations, central bank movements, economic and social conditions within a country, trade imbalances, or trade or currency restrictions between countries, as well as supply and demand for gold and operational costs associated with mining.

• Subsidiary Risk. Investment in an unregistered subsidiary is not subject to the investor protections of the Investment Company Act of 1940 (1940 Act) and is subject to the risks associated with the gold industry. Changes in tax and other laws could negatively affect investments in the subsidiary.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

Risk Lose Money [Text]

rr_RiskLoseMoney

<font style="FONT-FAMILY: Times New Roman" size="3">You could lose money by investing in the fund.</font>

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

<font style="FONT-FAMILY: Times New Roman" size="3">In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.</font>

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

<font style="FONT-FAMILY: Times New Roman" size="3">An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</font>

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

<font style="FONT-FAMILY: Times New Roman" size="3">The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time.</font>

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

<font style="FONT-FAMILY: Times New Roman" size="3">institutional.fidelity.com</font>

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

<font style="FONT-FAMILY: Times New Roman" size="3">Past performance (before and after taxes) is not an indication of future performance.</font>

Bar Chart [Heading]

rr_BarChartHeading

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	41.01%	March 31, 2016
Lowest Quarter Return	-37.34%	June 30, 2013
Year-to-Date Return	-8.09%	June 30, 2018

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

<font style="FONT-FAMILY: Times New Roman" size="3">* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.</font>

Performance Table Heading

rr_PerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

<font style="FONT-FAMILY: Times New Roman" size="3">After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.</font>

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

<font style="FONT-FAMILY: Times New Roman" size="3">The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).</font>

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

<font style="FONT-FAMILY: Times New Roman" size="3">Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.</font>

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | Fidelity Advisor Gold Fund: Class Z

Risk/Return:

rr_RiskReturnAbstract

Management fee

rr_ManagementFeesOverAssets

0.54%

Distribution and/or Service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.13%

^[1]

Acquired fund fees and expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.03%

^[2],[3]

Total annual operating expenses

rr_ExpensesOverAssets

0.70%

1 year

rr_ExpenseExampleYear01

$ 72

3 years

rr_ExpenseExampleYear03

224

5 years

rr_ExpenseExampleYear05

390

10 years

rr_ExpenseExampleYear10

$ 871

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | Fidelity Advisor Gold Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(20.53%)

2009

rr_AnnualReturn2009

38.03%

2010

rr_AnnualReturn2010

35.32%

2011

rr_AnnualReturn2011

(16.28%)

2012

rr_AnnualReturn2012

(12.36%)

2013

rr_AnnualReturn2013

(51.38%)

2014

rr_AnnualReturn2014

(8.46%)

2015

rr_AnnualReturn2015

(17.82%)

2016

rr_AnnualReturn2016

47.29%

2017

rr_AnnualReturn2017

8.58%

Year to Date Return, Label

rr_YearToDateReturnLabel

Year-to-Date Return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2018

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

(8.09%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarter Return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2016

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

41.01%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarter Return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2013

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(37.34%)

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | Return Before Taxes | Fidelity Advisor Gold Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Gold Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return Before Taxes</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

8.58%

Past 5 years

rr_AverageAnnualReturnYear05

(10.17%)

Past 10 years

rr_AverageAnnualReturnYear10

(4.41%)

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | After Taxes on Distributions | Fidelity Advisor Gold Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Gold Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

8.50%

Past 5 years

rr_AverageAnnualReturnYear05

(10.44%)

Past 10 years

rr_AverageAnnualReturnYear10

(4.94%)

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | After Taxes on Distributions and Sales | Fidelity Advisor Gold Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Gold Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions and Sale of Fund Shares</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

4.88%

Past 5 years

rr_AverageAnnualReturnYear05

(7.42%)

Past 10 years

rr_AverageAnnualReturnYear10

(2.98%)

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | S&P 500® Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

21.83%

Past 5 years

rr_AverageAnnualReturnYear05

15.79%

Past 10 years

rr_AverageAnnualReturnYear10

8.50%

NF_FA Gold Fund_Class Z PRO-01 | Gold Portfolio | S&P® Global BMI Gold Capped 20/45 Linked Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

11.59%

Past 5 years

rr_AverageAnnualReturnYear05

(9.89%)

Past 10 years

rr_AverageAnnualReturnYear10

(4.79%)

[1] Based on estimated amounts for the current fiscal year.

[2] Based on historical expenses, adjusted to reflect current fees.

[3] The fund may invest in a wholly-owned subsidiary. The subsidiary has entered into a separate contract with Fidelity Management &amp; Research Company (FMR), an affiliate of Fidelity SelectCo, LLC (SelectCo), the fund's investment adviser, for the management of its portfolio pursuant to which the subsidiary pays FMR a fee at an annual rate of 0.30% of its net assets. The subsidiary also pays certain other expenses including custody fees. SelectCo has contractually agreed to waive the fund's management fee in an amount equal to the management fee paid to FMR by the subsidiary. This arrangement will remain in effect for at least one year from the effective date of the prospectus, and will remain in effect thereafter as long as FMR's contract with the subsidiary is in place, and neither SelectCo nor any of its affiliates retain the ability to be repaid with respect to this arrangement. If FMR's contract with the subsidiary is terminated, SelectCo, in its sole discretion, may discontinue the arrangement.

XML

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Materials Portfolio</b>/Fidelity Advisor® Materials Fund Z</p>

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

The fund seeks capital appreciation.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

Shareholder Fees {- Materials Portfolio}	NF_FA Materials Fund_Class Z PRO-01 Materials Portfolio USD ($)
(fees paid directly from your investment)	none

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Annual Operating Expenses {- Materials Portfolio}	NF_FA Materials Fund_Class Z PRO-01 Materials Portfolio Fidelity Advisor Materials Fund: Class Z
Management fee	0.54%
Distribution and/or Service (12b-1) fees	none
Other expenses	0.11%	[1]
Total annual operating expenses	0.65%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Expense Example {- Materials Portfolio}	NF_FA Materials Fund_Class Z PRO-01 Materials Portfolio Fidelity Advisor Materials Fund: Class Z USD ($)
1 year	$ 66
3 years	208
5 years	362
10 years	$ 810

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 67% of the average value of its portfolio.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, mining, processing, or distribution of raw materials and intermediate goods.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Materials Industry Concentration. The materials industries can be significantly affected by the level and volatility of commodity prices, the exchange value of the dollar, import and export controls, worldwide competition, liability for environmental damage, depletion of resources, and mandated expenditures for safety and pollution control.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	26.47%	September 30, 2009
Lowest Quarter Return	-30.13%	December 31, 2008
Year-to-Date Return	-4.50%	June 30, 2018

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

Average Annual Total Returns{- Materials Portfolio} - NF_FA Materials Fund_Class Z PRO-01 - Materials Portfolio	Past 1 year	Past 5 years	Past 10 years
Fidelity Advisor Materials Fund: Class I | Return Before Taxes	26.21%	9.50%	7.62%
Fidelity Advisor Materials Fund: Class I | After Taxes on Distributions	24.61%	8.42%	6.96%
Fidelity Advisor Materials Fund: Class I | After Taxes on Distributions and Sales	16.02%	7.35%	6.11%
S&P 500® Index(reflects no deduction for fees, expenses, or taxes)	21.83%	15.79%	8.50%
MSCI U.S. IMI Materials 25-50 Index(reflects no deduction for fees, expenses, or taxes)	23.59%	12.35%	6.76%

[1] Based on estimated amounts for the current fiscal year.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY SELECT PORTFOLIOS

Prospectus Date

rr_ProspectusDate

Sep. 29, 2018

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Materials Portfolio</b>/Fidelity Advisor® Materials Fund Z</p>

Objective [Heading]

rr_ObjectiveHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

(fees paid directly from your investment)

rr_ShareholderFeeOther

none

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 67% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

67.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

<font style="FONT-FAMILY: Times New Roman" size="3">Based on estimated amounts for the current fiscal year.</font>

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Strategy [Heading]

rr_StrategyHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, mining, processing, or distribution of raw materials and intermediate goods.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

<font style="FONT-FAMILY: Times New Roman" size="3">Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture, mining, processing, or distribution of raw materials and intermediate goods.</font>

Risk [Heading]

rr_RiskHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Materials Industry Concentration. The materials industries can be significantly affected by the level and volatility of commodity prices, the exchange value of the dollar, import and export controls, worldwide competition, liability for environmental damage, depletion of resources, and mandated expenditures for safety and pollution control.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

Risk Lose Money [Text]

rr_RiskLoseMoney

<font style="FONT-FAMILY: Times New Roman" size="3">You could lose money by investing in the fund.</font>

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

<font style="FONT-FAMILY: Times New Roman" size="3">In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.</font>

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

<font style="FONT-FAMILY: Times New Roman" size="3">An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</font>

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

<font style="FONT-FAMILY: Times New Roman" size="3">The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time.</font>

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

<font style="FONT-FAMILY: Times New Roman" size="3">institutional.fidelity.com</font>

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

<font style="FONT-FAMILY: Times New Roman" size="3">Past performance (before and after taxes) is not an indication of future performance.</font>

Bar Chart [Heading]

rr_BarChartHeading

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	26.47%	September 30, 2009
Lowest Quarter Return	-30.13%	December 31, 2008
Year-to-Date Return	-4.50%	June 30, 2018

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

<font style="FONT-FAMILY: Times New Roman" size="3">* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.</font>

Performance Table Heading

rr_PerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

<font style="FONT-FAMILY: Times New Roman" size="3">After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.</font>

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

<font style="FONT-FAMILY: Times New Roman" size="3">The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).</font>

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | Fidelity Advisor Materials Fund: Class Z

Risk/Return:

rr_RiskReturnAbstract

Management fee

rr_ManagementFeesOverAssets

0.54%

Distribution and/or Service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.11%

^[1]

Total annual operating expenses

rr_ExpensesOverAssets

0.65%

1 year

rr_ExpenseExampleYear01

$ 66

3 years

rr_ExpenseExampleYear03

208

5 years

rr_ExpenseExampleYear05

362

10 years

rr_ExpenseExampleYear10

$ 810

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | Fidelity Advisor Materials Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(47.55%)

2009

rr_AnnualReturn2009

78.70%

2010

rr_AnnualReturn2010

28.11%

2011

rr_AnnualReturn2011

(8.20%)

2012

rr_AnnualReturn2012

20.17%

2013

rr_AnnualReturn2013

21.92%

2014

rr_AnnualReturn2014

(0.05%)

2015

rr_AnnualReturn2015

(8.65%)

2016

rr_AnnualReturn2016

12.04%

2017

rr_AnnualReturn2017

26.21%

Year to Date Return, Label

rr_YearToDateReturnLabel

Year-to-Date Return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2018

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

(4.50%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarter Return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

26.47%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarter Return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(30.13%)

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | Return Before Taxes | Fidelity Advisor Materials Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Materials Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return Before Taxes</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

26.21%

Past 5 years

rr_AverageAnnualReturnYear05

9.50%

Past 10 years

rr_AverageAnnualReturnYear10

7.62%

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | After Taxes on Distributions | Fidelity Advisor Materials Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Materials Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

24.61%

Past 5 years

rr_AverageAnnualReturnYear05

8.42%

Past 10 years

rr_AverageAnnualReturnYear10

6.96%

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | After Taxes on Distributions and Sales | Fidelity Advisor Materials Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Materials Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions and Sale of Fund Shares</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

16.02%

Past 5 years

rr_AverageAnnualReturnYear05

7.35%

Past 10 years

rr_AverageAnnualReturnYear10

6.11%

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | S&P 500® Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

21.83%

Past 5 years

rr_AverageAnnualReturnYear05

15.79%

Past 10 years

rr_AverageAnnualReturnYear10

8.50%

NF_FA Materials Fund_Class Z PRO-01 | Materials Portfolio | MSCI U.S. IMI Materials 25-50 Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

23.59%

Past 5 years

rr_AverageAnnualReturnYear05

12.35%

Past 10 years

rr_AverageAnnualReturnYear10

6.76%

[1] Based on estimated amounts for the current fiscal year.

XML

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Telecommunications Portfolio</b>/Fidelity Advisor® Telecommunications Fund Z</p>

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

The fund seeks capital appreciation.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

Shareholder Fees {- Telecommunications Portfolio}	NF_FA Telecommunications Fund_Class Z PRO-01 Telecommunications Portfolio USD ($)
(fees paid directly from your investment)	none

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Annual Operating Expenses {- Telecommunications Portfolio}	NF_FA Telecommunications Fund_Class Z PRO-01 Telecommunications Portfolio Fidelity Advisor Telecommunications Fund: Class Z
Management fee	0.54%
Distribution and/or Service (12b-1) fees	none
Other expenses	0.14%	[1]
Total annual operating expenses	0.68%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Expense Example {- Telecommunications Portfolio}	NF_FA Telecommunications Fund_Class Z PRO-01 Telecommunications Portfolio Fidelity Advisor Telecommunications Fund: Class Z USD ($)
1 year	$ 69
3 years	218
5 years	379
10 years	$ 847

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 66% of the average value of its portfolio.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the development, manufacture, or sale of communications services or communications equipment.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Telecom Services Industry Concentration. The telecom services industry is subject to government regulation and can be significantly affected by intense competition and technology changes.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	18.68%	June 30, 2009
Lowest Quarter Return	-21.99%	December 31, 2008
Year-to-Date Return	-4.18%	June 30, 2018

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

Average Annual Total Returns{- Telecommunications Portfolio} - NF_FA Telecommunications Fund_Class Z PRO-01 - Telecommunications Portfolio	Past 1 year	Past 5 years	Past 10 years
Fidelity Advisor Telecommunications Fund: Class I | Return Before Taxes	1.68%	9.95%	5.55%
Fidelity Advisor Telecommunications Fund: Class I | After Taxes on Distributions	(2.52%)	8.21%	4.58%
Fidelity Advisor Telecommunications Fund: Class I | After Taxes on Distributions and Sales	4.34%	7.70%	4.34%
S&P 500® Index(reflects no deduction for fees, expenses, or taxes)	21.83%	15.79%	8.50%
MSCI U.S. IMI Telecommunications Services 25-50 Index(reflects no deduction for fees, expenses, or taxes)	(5.71%)	8.93%	4.63%

[1] Based on estimated amounts for the current fiscal year.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY SELECT PORTFOLIOS

Prospectus Date

rr_ProspectusDate

Sep. 29, 2018

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Telecommunications Portfolio</b>/Fidelity Advisor® Telecommunications Fund Z</p>

Objective [Heading]

rr_ObjectiveHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

(fees paid directly from your investment)

rr_ShareholderFeeOther

none

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 66% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

66.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

<font style="FONT-FAMILY: Times New Roman" size="3">Based on estimated amounts for the current fiscal year.</font>

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Strategy [Heading]

rr_StrategyHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the development, manufacture, or sale of communications services or communications equipment.

• Investing in domestic and foreign issuers.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

<font style="FONT-FAMILY: Times New Roman" size="3">Normally investing at least 80% of assets in securities of companies principally engaged in the development, manufacture, or sale of communications services or communications equipment.</font>

Risk [Heading]

rr_RiskHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

• Telecom Services Industry Concentration. The telecom services industry is subject to government regulation and can be significantly affected by intense competition and technology changes.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. The value of securities of smaller issuers can be more volatile than that of larger issuers.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

Risk Lose Money [Text]

rr_RiskLoseMoney

<font style="FONT-FAMILY: Times New Roman" size="3">You could lose money by investing in the fund.</font>

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

<font style="FONT-FAMILY: Times New Roman" size="3">In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.</font>

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

<font style="FONT-FAMILY: Times New Roman" size="3">An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</font>

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

<font style="FONT-FAMILY: Times New Roman" size="3">The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time.</font>

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

<font style="FONT-FAMILY: Times New Roman" size="3">institutional.fidelity.com</font>

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

<font style="FONT-FAMILY: Times New Roman" size="3">Past performance (before and after taxes) is not an indication of future performance.</font>

Bar Chart [Heading]

rr_BarChartHeading

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	18.68%	June 30, 2009
Lowest Quarter Return	-21.99%	December 31, 2008
Year-to-Date Return	-4.18%	June 30, 2018

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

<font style="FONT-FAMILY: Times New Roman" size="3">* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.</font>

Performance Table Heading

rr_PerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

<font style="FONT-FAMILY: Times New Roman" size="3">After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.</font>

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

<font style="FONT-FAMILY: Times New Roman" size="3">The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).</font>

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

<font style="FONT-FAMILY: Times New Roman" size="3">Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.</font>

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | Fidelity Advisor Telecommunications Fund: Class Z

Risk/Return:

rr_RiskReturnAbstract

Management fee

rr_ManagementFeesOverAssets

0.54%

Distribution and/or Service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.14%

^[1]

Total annual operating expenses

rr_ExpensesOverAssets

0.68%

1 year

rr_ExpenseExampleYear01

$ 69

3 years

rr_ExpenseExampleYear03

218

5 years

rr_ExpenseExampleYear05

379

10 years

rr_ExpenseExampleYear10

$ 847

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | Fidelity Advisor Telecommunications Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(47.63%)

2009

rr_AnnualReturn2009

51.71%

2010

rr_AnnualReturn2010

18.38%

2011

rr_AnnualReturn2011

(4.25%)

2012

rr_AnnualReturn2012

18.63%

2013

rr_AnnualReturn2013

21.46%

2014

rr_AnnualReturn2014

3.56%

2015

rr_AnnualReturn2015

2.31%

2016

rr_AnnualReturn2016

22.80%

2017

rr_AnnualReturn2017

1.68%

Year to Date Return, Label

rr_YearToDateReturnLabel

Year-to-Date Return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2018

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

(4.18%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarter Return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

18.68%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarter Return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(21.99%)

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | Return Before Taxes | Fidelity Advisor Telecommunications Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Telecommunications Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return Before Taxes</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

1.68%

Past 5 years

rr_AverageAnnualReturnYear05

9.95%

Past 10 years

rr_AverageAnnualReturnYear10

5.55%

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | After Taxes on Distributions | Fidelity Advisor Telecommunications Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Telecommunications Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

(2.52%)

Past 5 years

rr_AverageAnnualReturnYear05

8.21%

Past 10 years

rr_AverageAnnualReturnYear10

4.58%

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | After Taxes on Distributions and Sales | Fidelity Advisor Telecommunications Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Telecommunications Portfolio

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions and Sale of Fund Shares</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

4.34%

Past 5 years

rr_AverageAnnualReturnYear05

7.70%

Past 10 years

rr_AverageAnnualReturnYear10

4.34%

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | S&P 500® Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

21.83%

Past 5 years

rr_AverageAnnualReturnYear05

15.79%

Past 10 years

rr_AverageAnnualReturnYear10

8.50%

NF_FA Telecommunications Fund_Class Z PRO-01 | Telecommunications Portfolio | MSCI U.S. IMI Telecommunications Services 25-50 Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

(5.71%)

Past 5 years

rr_AverageAnnualReturnYear05

8.93%

Past 10 years

rr_AverageAnnualReturnYear10

4.63%

[1] Based on estimated amounts for the current fiscal year.

XML

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Fidelity® International Real Estate Fund</b>/Fidelity Advisor® International Real Estate Fund Z</p>

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

The fund seeks capital appreciation.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

Shareholder Fees {- Fidelity International Real Estate Fund}	NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 Fidelity International Real Estate Fund USD ($)
(fees paid directly from your investment)	none

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Annual Operating Expenses {- Fidelity International Real Estate Fund}	NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 Fidelity International Real Estate Fund Fidelity Advisor International Real Estate Fund: Class Z
Management fee	0.69%
Distribution and/or Service (12b-1) fees	none
Other expenses	0.17%	[1]
Total annual operating expenses	0.86%

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Expense Example {- Fidelity International Real Estate Fund}	NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 Fidelity International Real Estate Fund Fidelity Advisor International Real Estate Fund: Class Z USD ($)
1 year	$ 88
3 years	274
5 years	477
10 years	$ 1,061

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 56% of the average value of its portfolio.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

• Normally investing primarily in non-U.S. securities.

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments.

• Allocating investments across different countries and regions.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile.

• Real Estate Industry Concentration. Changes in real estate values or economic downturns can have a significant negative effect on issuers in the real estate industry. The value of securities of issuers in the real estate industry can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements, and the management skill and creditworthiness of the issuer.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	35.24%	June 30, 2009
Lowest Quarter Return	-24.37%	December 31, 2008
Year-to-Date Return	0.26%	June 30, 2018

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

Average Annual Total Returns{- Fidelity International Real Estate Fund} - NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 - Fidelity International Real Estate Fund	Past 1 year	Past 5 years	Past 10 years
Fidelity Advisor International Real Estate Fund: Class I | Return Before Taxes	26.94%	8.40%	2.59%
Fidelity Advisor International Real Estate Fund: Class I | After Taxes on Distributions	25.62%	6.86%	1.27%
Fidelity Advisor International Real Estate Fund: Class I | After Taxes on Distributions and Sales	15.78%	5.97%	1.45%
MSCI EAFE Index(reflects no deduction for fees or expenses)	25.29%	8.07%	2.10%
FTSE® EPRA℠/NAREIT® Developed ex North America Index(reflects no deduction for fees, expenses, or taxes)	21.02%	5.87%	1.96%

[1] Based on estimated amounts for the current fiscal year.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY SELECT PORTFOLIOS

Prospectus Date

rr_ProspectusDate

Sep. 29, 2018

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p style="font: bold 20pt Arial, Helvetica, sans-serif;">Fund Summary</p><p style="font: normal 12pt Arial, Helvetica, sans-serif;"><b>Fund/Class</b>:<br/><b>Fidelity® International Real Estate Fund</b>/Fidelity Advisor® International Real Estate Fund Z</p>

Objective [Heading]

rr_ObjectiveHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;">Investment Objective</font>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Fee Table</b></font>

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund. In addition to the fees and expenses described below, your broker may also require you to pay brokerage commissions on purchases and sales of certain share classes of the fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Shareholder fees</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px"></p>

(fees paid directly from your investment)

rr_ShareholderFeeOther

none

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p style="font: bold 11pt Arial, sans-serif; margin-bottom: 0px;">Annual Operating Expenses</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">(expenses that you pay each year as a % of the value of your investment)</p>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Portfolio Turnover</b></font>

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 56% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

56.00%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

<font style="FONT-FAMILY: Times New Roman" size="3">Based on estimated amounts for the current fiscal year.</font>

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

<p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Sell All Shares</p>

Strategy [Heading]

rr_StrategyHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Strategies</b></font>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

• Normally investing primarily in non-U.S. securities.

• Normally investing primarily in common stocks.

• Normally investing at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments.

• Allocating investments across different countries and regions.

• Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

Strategy Portfolio Concentration [Text]

rr_StrategyPortfolioConcentration

<font style="FONT-FAMILY: Times New Roman" size="3">Normally investing at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments.</font>

Risk [Heading]

rr_RiskHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Principal Investment Risks</b></font>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

• Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

• Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile.

• Real Estate Industry Concentration. Changes in real estate values or economic downturns can have a significant negative effect on issuers in the real estate industry. The value of securities of issuers in the real estate industry can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements, and the management skill and creditworthiness of the issuer.

• Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole.

In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You could lose money by investing in the fund.

Risk Lose Money [Text]

rr_RiskLoseMoney

<font style="FONT-FAMILY: Times New Roman" size="3">You could lose money by investing in the fund.</font>

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

<font style="FONT-FAMILY: Times New Roman" size="3">In addition, the fund is classified as non-diversified under the Investment Company Act of 1940, which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.</font>

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

<font style="FONT-FAMILY: Times New Roman" size="3">An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</font>

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Performance</b></font>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time. The indexes have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit institutional.fidelity.com for more recent performance information.

Performance history will be available for Class Z after Class Z has been in operation for one calendar year.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

<font style="FONT-FAMILY: Times New Roman" size="3">The information illustrates the changes in the performance of Class I shares from year to year and compares the performance of Class I shares to the performance of a securities market index and an additional index over various periods of time.</font>

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

<font style="FONT-FAMILY: Times New Roman" size="3">institutional.fidelity.com</font>

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

<font style="FONT-FAMILY: Times New Roman" size="3">Past performance (before and after taxes) is not an indication of future performance.</font>

Bar Chart [Heading]

rr_BarChartHeading

<p style="font:bold 11pt Arial, sans-serif; margin-bottom: 0px;">Year-by-Year Returns*</p><p style="font: bold 9pt Arial, sans-serif; margin-top: 0px">Calendar Years</p>

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	35.24%	June 30, 2009
Lowest Quarter Return	-24.37%	December 31, 2008
Year-to-Date Return	0.26%	June 30, 2018

Bar Chart, Returns for Class Not Offered in Prospectus [Text]

rr_BarChartReturnsForClassNotOfferedInProspectus

<font style="FONT-FAMILY: Times New Roman" size="3">* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.</font>

Performance Table Heading

rr_PerformanceTableHeading

<font style="font: bold 16pt Arial, Helvetica, sans-serif;"><b>Average Annual Returns*</b></font>

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

<font style="FONT-FAMILY: Times New Roman" size="3">After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.</font>

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

<font style="FONT-FAMILY: Times New Roman" size="3">The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).</font>

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

<font style="FONT-FAMILY: Times New Roman" size="3">Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.</font>

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

For the periods ended December 31, 2017

* The returns shown above are for Class I, which is not offered through this prospectus. Class Z would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Class Z's returns would differ from Class I's returns to the extent that the classes do not have the same expenses.

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | Fidelity Advisor International Real Estate Fund: Class Z

Risk/Return:

rr_RiskReturnAbstract

Management fee

rr_ManagementFeesOverAssets

0.69%

Distribution and/or Service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.17%

^[1]

Total annual operating expenses

rr_ExpensesOverAssets

0.86%

1 year

rr_ExpenseExampleYear01

$ 88

3 years

rr_ExpenseExampleYear03

274

5 years

rr_ExpenseExampleYear05

477

10 years

rr_ExpenseExampleYear10

$ 1,061

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | Fidelity Advisor International Real Estate Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

2008

rr_AnnualReturn2008

(50.60%)

2009

rr_AnnualReturn2009

35.93%

2010

rr_AnnualReturn2010

14.56%

2011

rr_AnnualReturn2011

(22.26%)

2012

rr_AnnualReturn2012

44.22%

2013

rr_AnnualReturn2013

12.60%

2014

rr_AnnualReturn2014

4.28%

2015

rr_AnnualReturn2015

1.90%

2016

rr_AnnualReturn2016

(1.47%)

2017

rr_AnnualReturn2017

26.94%

Year to Date Return, Label

rr_YearToDateReturnLabel

Year-to-Date Return

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jun. 30, 2018

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

0.26%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarter Return

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

35.24%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarter Return

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(24.37%)

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | Return Before Taxes | Fidelity Advisor International Real Estate Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Fidelity International Real Estate Fund

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return Before Taxes</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

26.94%

Past 5 years

rr_AverageAnnualReturnYear05

8.40%

Past 10 years

rr_AverageAnnualReturnYear10

2.59%

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | After Taxes on Distributions | Fidelity Advisor International Real Estate Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Fidelity International Real Estate Fund

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

25.62%

Past 5 years

rr_AverageAnnualReturnYear05

6.86%

Past 10 years

rr_AverageAnnualReturnYear10

1.27%

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | After Taxes on Distributions and Sales | Fidelity Advisor International Real Estate Fund: Class I

Risk/Return:

rr_RiskReturnAbstract

Column

rr_AverageAnnualReturnColumnName

Fidelity International Real Estate Fund

Label

rr_AverageAnnualReturnLabel

<font style="FONT-FAMILY: Times New Roman" ><b>Return After Taxes on Distributions and Sale of Fund Shares</b></font>

Past 1 year

rr_AverageAnnualReturnYear01

15.78%

Past 5 years

rr_AverageAnnualReturnYear05

5.97%

Past 10 years

rr_AverageAnnualReturnYear10

1.45%

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | MSCI EAFE Index(reflects no deduction for fees or expenses)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

25.29%

Past 5 years

rr_AverageAnnualReturnYear05

8.07%

Past 10 years

rr_AverageAnnualReturnYear10

2.10%

NF_Fidelity Advisor International Real Estate Fund_Class Z PRO-01 | Fidelity International Real Estate Fund | FTSE® EPRA℠/NAREIT® Developed ex North America Index(reflects no deduction for fees, expenses, or taxes)

Risk/Return:

rr_RiskReturnAbstract

Past 1 year

rr_AverageAnnualReturnYear01

21.02%

Past 5 years

rr_AverageAnnualReturnYear05

5.87%

Past 10 years

rr_AverageAnnualReturnYear10

1.96%

[1] Based on estimated amounts for the current fiscal year.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	FIDELITY SELECT PORTFOLIOS
Prospectus Date	rr_ProspectusDate	Sep. 29, 2018
Document Creation Date	dei_DocumentCreationDate	Sep. 28, 2018