Director/PDMR Shareholding

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

Acquisition of notional ADSs within Dr Barron's GSK Executive Supplemental Savings Plan account following the reinvestment of dividends

c)

Price(s) and volume(s)

Price(s)

Volume(s)

$39.0300

2,552.047

d)

Aggregated information

N/A (single transaction)

Aggregated volume Price

e)

Date of the transaction

2021-05-20

f)

Place of the transaction

New York Stock Exchange (XNYS)

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

Acquisition of ADSs within Dr Barron's GSK 401(k) plan account following the reinvestment of dividends

c)

Price(s) and volume(s)

Price(s)

Volume(s)

$39.0300

67

d)

Aggregated information

N/A (single transaction)

Aggregated volume Price

e)

Date of the transaction

2021-05-20

f)

Place of the transaction

New York Stock Exchange (XNYS)

1.

Details of PDMR/person closely associated with them ('PCA')

a)

Name

Mr J Ford

b)

Position/status

SVP & 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

Acquisition of notional ADSs within Mr Ford's GSK Executive Supplemental Savings Plan account following the reinvestment of dividends

c)

Price(s) and volume(s)

Price(s)

Volume(s)

$39.0300

65.537

d)

Aggregated information

N/A (single transaction)

Aggregated volume Price

e)

Date of the transaction

2021-05-20

f)

Place of the transaction

New York Stock Exchange (XNYS)