UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of October 2021

Commission File Number 001-15170

GlaxoSmithKline plc

(Translation of registrant's name into English)

980 Great West Road, Brentford, Middlesex, TW8 9GS

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F . . . .X. . . . Form 40-F . . . . . . . .

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ____

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ____

GlaxoSmithKline plc (the 'Company')

Transaction notification

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Ms E Walmsley
b)	Position/status	Chief Executive Officer
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	956
			£14.0080	769
			£14.0080	640
d)	Aggregated information	2,365
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr I Mackay
b)	Position/status	Chief Financial Officer
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	519
			£14.0080	443
d)	Aggregated information	962
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Dr H Barron
b)	Position/status	Chief Scientific Officer and President, R&D
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	American Depositary Shares ('ADSs') ISIN: US37733W1053
b)	Nature of the transaction	Increase in notional interest in ADSs following the re-investment of dividends paid to shareholders on 7 October 2021 on ADSs held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			$38.6600	557
			$38.6600	437
			$38.6600	331
d)	Aggregated information	1,325
	Aggregated volume Price	$38.6600
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	New York Stock Exchange (XNYS)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr R Connor
b)	Position/status	President, Vaccines & Global Health
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	250
			£14.0080	242
			£14.0080	140
d)	Aggregated information	632
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Ms D Conrad
b)	Position/status	SVP Human Resources
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	100
			£14.0080	92
d)	Aggregated information	192
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr J Ford
b)	Position/status	Senior Vice President and General Counsel
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	142
			£14.0080	111
d)	Aggregated information	253
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr J Ford
b)	Position/status	Senior Vice President and General Counsel
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	American Depositary Shares ('ADSs') ISIN: US37733W1053
b)	Nature of the transaction	Increase in notional interest in ADSs following the re-investment of dividends paid to shareholders on 7 October 2021 on ADSs held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			$38.6600	47
d)	Aggregated information	N/A (single transaction)
	Aggregated volume Price
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	New York Stock Exchange (XNYS)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Ms S Jackson
b)	Position/status	SVP, Global Communications & CEO Office
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	60
			£14.0080	56
d)	Aggregated information	116
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr B McNamara
b)	Position/status	CEO, GSK Consumer Healthcare
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	American Depositary Shares ('ADSs') ISIN: US37733W1053
b)	Nature of the transaction	Increase in notional interest in ADSs following the re-investment of dividends paid to shareholders on 7 October 2021 on ADSs held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			$38.6600	93
			$38.6600	80
			$38.6600	101
d)	Aggregated information	274
	Aggregated volume Price	$38.6600
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	New York Stock Exchange (XNYS)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr L Miels
b)	Position/status	Chief Commercial Officer
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	266
			£14.0080	232
			£14.0080	173
d)	Aggregated information	671
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr D Redfern
b)	Position/status	Chief Strategy Officer
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	237
			£14.0080	170
			£14.0080	136
d)	Aggregated information	543
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr R Simard
b)	Position/status	President, Pharmaceuticals Supply Chain
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	85
			£14.0080	120
			£14.0080	102
d)	Aggregated information	307
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Ms K Terrell
b)	Position/status	Chief Digital & Technology Officer
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	American Depositary Shares ('ADSs') ISIN: US37733W1053
b)	Nature of the transaction	Increase in notional interest in ADSs following the re-investment of dividends paid to shareholders on 7 October 2021 on ADSs held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			$38.6600	118
			$38.6600	81
			$38.6600	63
d)	Aggregated information	262
	Aggregated volume Price	$38.6600
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	New York Stock Exchange (XNYS)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Mr P Thomson
b)	Position/status	President, Global Affairs
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	138
			£14.0080	98
			£14.0080	79
d)	Aggregated information	315
	Aggregated volume Price	£14.0080
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

1.	Details of PDMR/person closely associated with them ('PCA')
a)	Name	Ms D Waterhouse
b)	Position/status	Chief Executive Officer of ViiV Healthcare
c)	Initial notification/amendment	Initial notification
2.	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	GlaxoSmithKline plc
b)	LEI	5493000HZTVUYLO1D793
3.	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transaction(s) has been conducted
a)	Description of the financial instrument	Ordinary shares of 25 pence each ('Ordinary Shares') ISIN: GB0009252882
b)	Nature of the transaction	Increase in notional interest in Ordinary Shares following the re-investment of dividends paid to shareholders on 7 October 2021 on Ordinary Shares held in the Company's Deferred Annual Bonus Plan
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			£14.0080	163
d)	Aggregated information	N/A (single transaction)
	Aggregated volume Price
e)	Date of the transaction	2021-10-11
f)	Place of the transaction	London Stock Exchange (XLON)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorised.

	GlaxoSmithKline plc
	(Registrant)
Date: October 14, 2021
	By:/s/ VICTORIA WHYTE --------------------------
	Victoria Whyte
	Authorised Signatory for and on
	behalf of GlaxoSmithKline plc