X0306 4 2017-08-14 0001140536 WILLIS TOWERS WATSON PLC WLTW 0001223628 ONEILL BRENDAN R C/O WILLIS GROUP LIMITED 51 LIME STREET LONDON X0 EC3M 7DQ UNITED KINGDOM 1 Ordinary Shares, nominal value $0.000304635 per share 2017-08-14 4 A 0 991 0 A 17302 D Ordinary Shares, nominal value $0.000304635 per share 2017-08-15 4 F 0 514 151.31 D 16788 D Ordinary Shares, nominal value $0.000304635 per share 2017-08-16 4 S 0 5000 150.9226 D 11788 D Comprised of 991 restricted share units ("RSUs"), which represent the right to receive ordinary shares, par value $0.000304635 per share, of the Issuer. The RSUs shall vest in full on August 14, 2018. Withholding of shares by Issuer incident to the tax payment related to the vesting and settlement of 1,069 RSUs granted on August 15, 2016. Includes 991 RSUs noted in footnote (1). This transaction was executed in multiple trades at prices ranging from $150.84 to $150.98. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. /s/ Brendan R. O'Neill by Elaine Wiggins, Attorney-in-Fact (power of attorney previously filed) 2017-08-16