b. ?1740, 1st s. of Sir Kenrick Clayton, 2nd Bt.†, of Marden by Henrietta Maria, da. and coh. of Henry Herring of Mincing Lane, London, dir. Bank of England. educ. ?Eton 1753-8; Clare, Camb. 1758. m. 1 June 1767, Mary, da. of Frederick Standert† of Greenwich, Kent, s.p. suc. fa. as 3rd Bt. 10 Mar. 1769.
Clayton joined the Whig Club, 6 Dec. 1784. Ousted from his county seat earlier that year, he was out of the House until 1787, when he came in for Bletchingley, of which his family had been proprietors for two generations. In financial difficulties, he had sold the reversion of that property to his cousin John Kenrick† in 1779 for £10,000 and failed to recover it from him by a suit in Chancery decided against him in 1788. In 1790 he ceased to return Kenrick for Bletchingley and sold the second seat to another Whig.
Clayton made no mark in the first three sessions of the Parliament of 1790. He was reckoned hostile to the repeal of the Test Act in Scotland in 1791. He was listed a Portland Whig in December 1792 and seceded from the Whig Club. But in 1794 he returned to his allegiance to Fox, voting for his motion on convoy protection, 18 Feb., for Whitbread’s motion for a separate peace with France, 6 Mar., and for Fox’s against the war, 30 May. He further voted for peace negotiations on 26 Jan., 6 Feb., 24 Mar. and 27 May 1795. He was in the minority on the question of the Prince of Wales’s debts, 1 June. He voted against the seditious meetings bill, 25 Nov. 1795, and for Grey’s motion on the cost of the war effort, 10 Mar. 1796. Both in 1790 and in 1796 he proposed Lord William Russell* as county Member.
Clayton died 10 May 1799 ‘in his 60th year’, whereupon his electoral patronage reverted to the Kenrick family.
A state of the dispute between Sir Robert Clayton ... and John Kenrick, relative to the purchase of the manor and borough of Bletchingley; Gent. Mag. (1799), i. 445.