William Jolliffe, 4th Baron Hylton

William George Hervey Jolliffe, 4th Baron Hylton (2 December 1898 – 14 November 1967), was a British peer and soldier.

Hylton was the son of Hylton Jolliffe, 3rd Baron Hylton, and Lady Alice Adeliza Hervey. He achieved the rank of Lieutenant-Colonel in the Coldstream Guards and also served as Lord Lieutenant of Somerset from 1949 to 1964. Lord Hylton married Lady Perdita Rose Mary Asquith, daughter of Katharine and Raymond Asquith, eldest son of Prime Minister H. H. Asquith, in 1931. He died in November 1967, aged 68.

He was succeeded in his titles by his elder son Raymond. John Hedworth Jolliffe, a writer (of e.g. Raymond Asquith: Life and Letters) is his younger son; his daughter Mary is the wife of John Paget Chancellor, son of Christopher Chancellor of Reuters. Mary and John Chancellor are the parents of the actress Anna Chancellor and the financial historian Edward Chancellor.