William Pether (c. 1739 – 19 July 1821) was primarily an English mezzotint engraver, but also decorated porcelain, made oil paintings and pastel drawings, and invented gadgets.

Pether was a fellow of the Incorporated Society of Artists and contributed to its exhibitions' paintings, miniatures, and engravings from 1764 to 1777.

Pether died in Montague Street, Bristol, on 19 July 1821, aged 82 or 83, having long been forgotten in the art world.

Pether engraved altogether about fifty plates, some of which were published by John Boydell, but the majority by himself at various addresses in London.

Pether was also a miniaturist and painted some life-sized portraits in oil, three of which—Sarah Bates the singer, the brothers Smith of Chichester, and himself in Spanish dress—he also engraved.