William Jolliffe, 1st Baron Hylton

William George Hylton Jolliffe, 1st Baron Hylton PC (7 December 1800 – 1 June 1876), known as Sir William Jolliffe, Bt, between 1821 and 1866, was a British soldier and Conservative politician. He was a member of the Earl of Derby's first two administrations as Under-Secretary of State for the Home Department in 1852 and as Parliamentary Secretary to the Treasury between 1858 and 1859.

Jolliffe was the son of Reverend William John Jolliffe, the son of William Jolliffe, and his wife Eleanor Hylton, daughter and heir of Sir Richard Hylton, 5th Baronet (who had assumed the surname of Hylton in lieu of his patronymic Musgrave; see Musgrave Baronets) and his wife Anne, sister and co-heiress of John Hylton, de jure 18th Baron Hylton. Jolliffe first served in the Army and achieved the rank of Captain in the 15th Dragoons. He notably took part in the events at St Peter's Field in Manchester in 1819 (the "Peterloo Massacre"). In 1821, at the age of twenty, Jolliffe was created a Baronet, of Merstham in the County of Surrey.

Jolliffe served a year as High Sheriff of Surrey in 1830 and then sat as a Member of Parliament for Petersfield from 1830 to 1832, 1837 to 1838 and 1841 to 1866 and served under the Earl of Derby as Under-Secretary of State for the Home Department in 1852 and as Parliamentary Secretary to the Treasury from 1858 to 1859. He was admitted to the Privy Council in 1859 and in 1866 he was raised to the peerage as Baron Hylton, of Hylton in the County Palatine of Durham and of Petersfield in the County of Southampton.

Jolliffe played a single first-class match for pre-county club Hampshire in 1825 against pre-county club Sussex. Jolliffe scored 12 runs in the match.

Lord Hylton married, firstly, Eleanor Paget, daughter of the Hon. Berkeley Thomas Paget, in 1825. Their eldest son Hylton Jolliffe was a Captain in the Coldstream Guards but died from cholera during the Crimean War. Hylton married, secondly, Sophia Penelope, daughter of Sir Robert Sheffield, 4th Baronet, and widow of William Fox-Strangways, 4th Earl of Ilchester, in 1867. He died at Merstham House near Reigate on 1 June 1876, aged 75, and was succeeded in his titles by his second but eldest surviving son from his first marriage, Hedworth.