The family derived its surname from the manor of Trevelyan in the parish of St Veep, Cornwall, situated in the ancient hundred of West Wivel, called Trewellen in the Domesday Book of 1086,[3] and shown in the British Ordnance Survey map of 1890 as located about one mile east of Penpoll.
[6] Prominent members of the senior branch included: The Venerable George Trevelyan (third son of the 4th Baronet), Archdeacon of Taunton in Somerset.
His younger son Sir Ernest John Trevelyan[8][9] (1850–1929) was a Judge of the High Court of Calcutta, a writer on legal matters and a member of the Oxford Town Council.
The estate of Wallington was inherited by Sir George Trevelyan, 3rd Baronet (1707–1768) from his wife Julia Calverley, daughter of Sir Walter Calverley, 1st Baronet, and his wife Julia Blackett, heiress of Wallington Castle, rebuilt by the Blacketts in the 1689s, who purchased it from the Fenwick family.
[11] In 2023, at least 42 members of the Trevelyan family signed a formal apology to victims of slavery, and donated a fund to pay voluntary reparations.