George Guy Greville, 4th Earl of Warwick, 4th Earl Brooke (28 March 1818 – 2 December 1893), styled Lord Brooke from 1818 to 1853, was an English Tory politician.
Greville was born in Charles Street, Berkeley Square, London. He was the only child of Henry Greville, 3rd Earl of Warwick, and Lady Sarah Elizabeth Savile, eldest daughter of John Savile, 2nd Earl of Mexborough. He was educated at St John's College, Oxford, from where he obtained a BA in 1839. He was Member of Parliament (MP) for South Warwickshire from 1845 to 1853, when he succeeded to the peerage. He served as honorary colonel to the Warwickshire Yeomanry cavalry, and as A.D.C. to Queen Victoria.
On 18 February 1852, he married Anne Charteris (1829–1903), daughter of Francis Wemyss-Charteris, 9th Earl of Wemyss. They had four children: Francis (1853–1924), Alwyn (1854–1929), Louis (1866–1927) and Sydney (1866–1927).
He joined the Canterbury Association on 11 February 1850 and was, from the day of joining, a member of the management committee. He died at Warwick Castle on 2 December 1893.
George was also a prolific contributor to the improvements of Warwick Castle during the nineteenth century. He oversaw the redecoration of the castle's Great Hall and domestic apartments after the fire of 1871. The celebrated architect Anthony Salvin was employed to rebuild the hall in the typical Victorian 'Gothic' taste, embellished with stain glass to achieve the effect of a medieval baronial hall. The domestic apartments were also redesigned, with each room assigned a different 'historical' style, typical of the nineteenth century interest in the 'Romantic Interior'. He was thought of as being extremely creative with his designs.