William Gwyn Vaughan (c. 1681–1753) of Trebarried, Breconshire, was a Welsh Tory politician who sat in the House of Commons from 1721 to 1734.
Vaughan was the second son of Gwyn Vaughan of Trebarried and his wife Mary Lucy, daughter of William Lucy, Bishop of St David's.
He matriculated at Queen's College, Oxford on 12 May 1698, aged 16.
He spoke against the Government in 1730 on the Hessians and in 1733 on the army estimates, and voted in 1733 against the Excise Bill and in 1734 for the repeal of the Septennial Act.
He had six sons including Gwyn, John, Thomas and Walter and two daughters Mary and Frances.