William Marmion (c. 1461 – 1529) of Adwell was an English gentleman who served as one of the Members of Parliament for Gloucester in 1491.

He was the son of William Marmion of Henley-on-Thames,[3] Steward of Dorchester Abbey and Recorder of Oxford.

[4] William Marmion was elected to Parliament on 17 October 1491.

[3] He was the grandfather of John Marmion MP for Cricklade in 1558.

This article about a 15th-century member of the parliament of England is a stub.