William Faithorne, often "the Elder", was an English painter and engraver.

Faithorne was born in London and was apprenticed to William Peake. On the outbreak of the Civil War Faithorne accompanied his master into the king's service, and being made prisoner at Basing House, he was confined for some time to Aldersgate, where, however, he was permitted to follow his profession of engraver, and among other portraits did a small one of George Villiers, 1st Duke of Buckingham.

At the earnest solicitation of his friends Faithorne very soon regained his liberty, but only on condition of retiring to France, where he received instruction from Robert Nanteuil. He was permitted to return to England in about 1650, and took a shop near Temple Bar, where, besides his work as an engraver, he carried on a large business as a print-seller.

In 1680 Faithorne gave up his shop and retired to a house in Blackfriars, occupying himself chiefly in painting portraits from the life in crayons, although still occasionally engaged in engraving. It is said that his life was shortened by the misfortunes, dissipation, and early death of his son William. He was buried in the church of St Ann Blackfriars on 13 May 1691.