William Mountfort (c. 1664 – 10 December 1692), English actor and dramatic writer, was the son of a Staffordshire gentleman.
His first stage appearance was with the Dorset Garden company about 1678, and by 1682 he was taking important parts, usually those of the fine gentleman. Mountfort wrote a number of plays, wholly or in part, and many prologues and epilogues. He married, in 1686, Susanna Percival, the actress.