Colonel Lord Arthur William Hill PC, DL, JP (28 July 1846 – 13 January 1931), was an Anglo-Irish soldier and Conservative politician. He served three times as Comptroller of the Household between 1885 and 1898 in the Conservative administrations headed by Lord Salisbury.

Hill was a younger son of Arthur Hill, 4th Marquess of Downshire, by his wife the Honourable Caroline Frances Stapleton-Cotton, daughter of Field Marshal Stapleton Stapleton-Cotton, 1st Viscount Combermere. Arthur Hill, 5th Marquess of Downshire, was his elder brother.^[1]

Hill served as a lieutenant in the 2nd Life Guards. He was later a lieutenant-colonel in the part-time 2nd Middlesex Royal Garrison Artillery (Volunteers), and was appointed an honorary colonel of the 5th (Militia) Battalion of the Royal Irish Rifles on 5 April 1902.^[2][1]

Hill sat as Member of Parliament for Down and subsequently for West Down from 1880 (succeeding his uncle Lord Edwin Hill-Trevor) until 1898, when he resigned from Parliament in June by becoming Steward of the Manor of Northstead.^[1][3] He served under Lord Salisbury as Comptroller of the Household from 1885^[4] to 1886,^[5] from 1886^[6] to 1892^[7] and from 1895^[8] to 1898.^[9] In 1885 he was sworn of the Privy Council.^[10] He again held the Down West seat briefly from 1907 to 1908.^[1][3] Apart from his political career he was also a Deputy Lieutenant of County Down and a Justice of the Peace for County Down and Berkshire.^[1]

Hill was twice married. He married firstly Annie Nisida Denham Cookes, daughter of Lieutenant-Colonel George Denham Cookes, in 1873. They had one son, Arthur Hill, who succeeded his father as MP for West Down in 1898. Lady Arthur Hill died in January 1874, shortly after the birth of her only child. Hill married as his second wife Annie Harrison, daughter of James Fortescue Harrison, MP for Kilmarnock, in 1877. They had one daughter. Hill died in January 1931, aged 84. Lady Arthur Hill died in February 1944.^[1]