As filed with the Securities and Exchange Commission on June 20, 2016

Registration No. 333-            

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

BOK FINANCIAL CORPORATION

(Exact name of registrant as specified in its charter)

Oklahoma

(State or other jurisdiction of

incorporation or organization)

73-1373454

(I.R.S. Employer

Identification Number)

Bank of Oklahoma Tower

Boston Avenue at Second Street

Tulsa, Oklahoma 74192

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Frederic Dorwart

General Counsel & Corporate Secretary

Frederic Dorwart, Lawyers

124 E. 4^th Street

Old City Hall

Tulsa, Oklahoma 74103

Telephone No.: 918-583-9922

Facsimile No.: 918-583-8251

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Mark J. Welshimer, Esq.

Sullivan & Cromwell LLP

125 Broad Street

New York, NY 10004

(212)-558-4000

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  x

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ¨

CALCULATION OF REGISTRATION FEE

Title of Each Class of Securities to be Registered	Amount to be Registered(1)	Proposed Maximum Offering Price Per Security(1)	Proposed Maximum Aggregate Offering Price(1)	Amount of Registration Fee(2)
Subordinated Debt Securities

1. An indeterminate amount of securities to be offered at indeterminate prices are being registered pursuant to this registration statement.

2. In accordance with Rule 456(b) and Rule 457(r) under the Securities Act, the registrant is deferring payment of all of the registration fees.

PROSPECTUS

BOK Financial Corporation

Subordinated Debt Securities

The securities listed above may be offered and sold by us and/or may be offered and sold, from time to time, by one or more selling security holders to be identified in the future. We will provide the specific terms of these securities in supplements to this prospectus. You should read this prospectus and the applicable prospectus supplement carefully before you invest in the securities described in the applicable prospectus supplement.

Investing in our securities involves risks. See “Risk Factors” in our most recent annual report on Form 10-K, which is incorporated herein by reference, in any of our subsequently filed quarterly and current reports that are incorporated herein by reference and in any applicable prospectus supplement.

We may offer and sell these securities to or through one or more underwriters, dealers and agents, or directly to purchasers, on a continuous or delayed basis.

This prospectus may not be used to sell securities unless accompanied by the applicable prospectus supplement.

These securities will be our unsecured obligations and will not be savings accounts, deposits or other obligations of any bank or non-bank subsidiary of ours and are not insured by the Federal Deposit Insurance Corporation or any other governmental agency or instrumentality.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined that this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Prospectus dated June 20, 2016.

No dealer, salesperson or other person is authorized to give any information or to represent anything not contained in this prospectus or the accompanying prospectus supplement. You must not rely on any unauthorized information or representations. This prospectus and the accompanying prospectus supplement together are an offer to sell only the securities offered hereby and thereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus and accompanying prospectus supplement is current only as of its date.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS	1
WHERE YOU CAN FIND MORE INFORMATION	2
RATIOS OF EARNINGS TO FIXED CHARGES	3
USE OF PROCEEDS	4
VALIDITY OF SECURITIES	4
EXPERTS	4

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ABOUT THIS PROSPECTUS

This prospectus is a part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration statement, we may sell subordinated debt securities.

Each time we sell securities we will provide a prospectus supplement containing specific information about the terms of the securities being offered. The prospectus supplement may include a discussion of any risk factors or other special considerations that apply to those securities. The prospectus supplement may also add, update or change the information in this prospectus. If there is any inconsistency between the information in this prospectus (including the information incorporated by reference herein) and any prospectus supplement, you should rely on the information in the applicable prospectus supplement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

The registration statement containing this prospectus, including exhibits to the registration statement, provides additional information about us and the securities offered under this prospectus. The registration statement can be read at the SEC website or at the SEC offices mentioned under the heading “Where You Can Find More Information.”

Unless otherwise indicated or unless the context requires otherwise, all references in this prospectus to “BOK Financial”, “we”, “us”, “our” or similar references mean BOK Financial Corporation.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document we file at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on its public reference room. In addition, our SEC filings are available to the public at the SEC’s website at http://www.sec.gov and on our website at https://www.bokf.com. We have included the SEC’s web address and our web address as inactive textual references only. Except as specifically incorporated by reference in this prospectus, information on those websites is not part of this prospectus.

The SEC allows us to “incorporate by reference” into this prospectus the information in documents we file with it. This means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus and should be read with the same care. When we update the information contained in documents that have been incorporated by reference by making future filings with the SEC, the information incorporated by reference in this prospectus is considered to be automatically updated and superseded. In other words, in the case of a conflict or inconsistency between information contained in this prospectus and information incorporated by reference into this prospectus, you should rely on the information contained in the document that was filed later. We incorporate by reference the documents listed below and any documents we file with the SEC after the date of this prospectus under Section 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) and before the date that the offering of securities by means of this prospectus is completed:

• Annual Report on Form 10-K for the year ended December 31, 2015;

• Quarterly Report on Form 10-Q for the quarter ended March 31, 2016

• Current Reports on Form 8-K filed on the following dates: March 14, 2016 and April 28, 2016 (Item 5.07, Accession No. 0000875357-16-000033).

Unless stated otherwise in the applicable report, information furnished under Item 2.02 or 7.01 of our Current Reports on Form 8-K, including those listed above, is not incorporated herein by reference.

You may request a copy of any of these filings, other than an exhibit to a filing unless that exhibit is specifically incorporated by reference into that filing, at no cost, by writing to or telephoning us at the following address:

BOK Financial Corporation

Attention: Corporate Secretary

124 E. 4^th Street

Tulsa, Oklahoma 74103

(918) 583-9922

Other than any documents expressly incorporated by reference, the information on our website and any other website that is referred to in this prospectus is not part of this prospectus.

You should rely only on the information incorporated by reference or presented in this prospectus or the applicable prospectus supplement. Neither we, nor any underwriters, dealers or agents, have authorized anyone else to provide you with different information. We may only use this prospectus to sell securities if it is accompanied by a prospectus supplement. We are only offering these securities in jurisdictions where the offer is permitted. You should not assume that the information in this prospectus or the applicable prospectus supplement is accurate as of any date other than the dates of those documents.

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RATIO OF EARNINGS TO FIXED CHARGES

Our consolidated ratio of earnings to fixed charges for each of the periods indicated is as follows:

Three Months Ended March 31,

Years Ended December 31,

2016

2015

2015

2014

2013

2012

2011

Ratio of Earnings to Fixed Charges:

Excluding interest on deposits

6.80x

17.57x

16.57x

18.80x

21.80x

20.85x

12.81x

Including interest on deposits

3.93x

6.99x

7.00x

6.83x

7.12x

6.78x

4.54x

The ratio of earnings to fixed charges is calculated in accordance with SEC requirements and computed by dividing earnings by fixed charges. For purposes of computing our ratio of earnings to fixed charges, earnings consist of net income before taxes plus fixed charges. Fixed charges, excluding interest on deposits, consist of interest expense and one-third of our rental expense, which we estimate to represent interest.

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USE OF PROCEEDS

We intend to use the net proceeds from the sales of the securities for general corporate purposes unless otherwise specified in the applicable prospectus supplement.

VALIDITY OF SECURITIES

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities will be passed upon for us by our counsel, Frederic Dorwart, Lawyers. Frederic Dorwart, Lawyers may rely on Sullivan & Cromwell LLP for certain New York law matters, and Sullivan & Cromwell LLP will rely on Frederic Dorwart, Lawyers for Oklahoma law matters. Any underwriters will be represented by their own legal counsel. Frederic Dorwart, Lawyers and certain of its members are indebted to and have other banking and trust relationships with BOK Financial. Frederic Dorwart, of Frederic Dorwart, Lawyers, is secretary and general counsel of BOK Financial.

EXPERTS

The consolidated financial statements of BOK Financial incorporated by reference in BOK Financial’s Annual Report (Form 10-K) for the year ended December 31, 2015, and the effectiveness of BOK Financial’s internal control over financial reporting as of December 31, 2015, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon, included herein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The following table sets forth the various expenses to be incurred in connection with the sale and distribution of the securities being registered hereby, all of which will be borne by BOK Financial. All amounts shown are estimates.

	Amount to be paid
SEC registration fee	$	(1	)
Listing fees		(2	)
Legal fees and expenses		(2	)
Fees and expenses of qualification under state securities laws (including legal fees)		(2	)
Accounting fees and expenses		(2	)
Printing fees		(2	)
Rating agency fees		(2	)
Trustee and depositary fees and expenses		(2	)
Miscellaneous		(2	)
Total	$

(1) To be determined. BOK Financial is deferring payment of the registration fee in reliance on Rule 456(b) and Rule 457(r) under the Securities Act of 1933.

(2) To be determined. These fees are calculated based on the number of issuances and amount securities offered and accordingly cannot be estimated at this time.

Item 15. Indemnification of Directors and Officers

Section 1031 of the Oklahoma General Corporation Act, under which BOK Financial is incorporated, permits, and in some circumstances requires, BOK Financial to indemnify its directors and officers. Article VI of the Bylaws of BOK Financial provides for indemnification of directors and officers under certain circumstances. As permitted by the Oklahoma General Corporation Act and BOK Financial’s Bylaws, BOK Financial also maintains insurance on behalf of its directors and officers against liability arising out of their status as such. The foregoing indemnity provisions, together with director and officer insurance and BOK Financial’s indemnification obligations under individual indemnity agreements with its directors and officers, may be sufficiently broad to indemnify such persons for liabilities under the Securities Act of 1933, as amended.

BOK Financial’s Bylaws provide for indemnification of each of BOK Financial’s officers and directors against expenses, including attorneys’ fees, judgments, fines and amounts paid in settlement actually and reasonably incurred by them in connection with any action, suit or proceeding brought by reason of such person being or having been a director, officer, employee or agent of BOK Financial, or of any other corporation, partnership, joint venture, trust or other enterprise at the request of BOK Financial, other than an action by or in the right of BOK Financial. To be entitled to such indemnification, the individual must have acted in good faith and in a manner he/she reasonably believed to be in or not opposed to the best interests of BOK Financial, and with respect to any criminal action or proceeding, the person seeking indemnification had no reasonable cause to believe that the conduct was unlawful. Subject to such limitations, the BOK Financial Bylaws grant indemnity to the full extent permissible under the law, but do not grant indemnity with respect to, mattes as to which indemnification would be in contravention of the laws of the State of Oklahoma or the United States of America, whether as a matter of public policy or pursuant to statutory provision.

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Item 16. Exhibits

The following exhibits are filed herewith or incorporated herein by reference unless otherwise indicated:

Exhibit No.	Description of Document
1.1	Form of Underwriting Agreement for Subordinated Debt Securities.*
4.1	Form of Subordinated Notes Indenture between BOK Financial Corporation and U.S. Bank National Association, as Trustee.
5.1   5.2	Opinion of Frederic Dorwart, Lawyers. Opinion of Sullivan & Cromwell LLP.
12.1	Computation of Ratio of Earnings to Fixed Charges.
23.1	Consent of Ernst & Young LLP.
23.2 23.3	Consent of Frederic Dorwart, Lawyers (included in Exhibit 5.1). Consent of Sullivan & Cromwell LLP (included in Exhibit 5.2).
24.1	Powers of attorney.
25.1	Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939, as amended, of U.S. Bank National Association, as Trustee under the Subordinated Notes Indenture.

* To be filed by amendment or as an exhibit to a document to be incorporated by reference herein in connection with an offering of the offered securities.

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Item 17. Undertakings

Each of the undersigned registrants hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that the undertakings set forth in paragraphs (i), (ii) and (iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for purposes of determining any liability under the Securities Act of 1933 to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such

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effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of a registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of such undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, such undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of such undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of such undersigned registrant or used or referred to by such undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of such undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by such undersigned registrant to the purchaser.

(6) That, for purposes of determining any liability under the Securities Act of 1933, each filing of its annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of each registrant pursuant to the foregoing provisions, or otherwise, the registrants have been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by a registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, that registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, each registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Tulsa, State of Oklahoma, on June 20, 2016.

BOK FINANCIAL CORPORATION
By:	/s/ STEVEN E. NELL
	Steven E. Nell Executive Vice President And Chief Financial Officer

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Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated and on June 20, 2016.

Signature	Title
/s/ STEVEN G. BRADSHAW Steven G. Bradshaw	Director, President and Chief Executive Officer (Principal Executive Officer)
/s/ STEVEN E. NELL Steven E. Nell	Chief Financial Officer (Principal Financial Officer and Principal Accounting Officer)
* Alan S. Armstrong	Director
* George B. Kaiser	Chairman of the Board of Directors
* C. Fred Ball, Jr.	Director
* Peter C. Boylan, III	Director
* Chester Cadieux, III	Director
* John W. Gibson	Director
* David F. Griffin	Director
* V. Burns Hargis	Director
*
Douglas D. Hawthorne	Director
* E. Carey Joullian, IV	Director
* Stanley A. Lybarger	Director

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* Steven J. Malcolm	Director
* E.C. Richards	Director
* Michael C. Turpen	Director
* R.A. Walker	Director

*By	/s/ STEVEN E. NELL
	Attorney-in-Fact

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