William Marlott (May 1574 – February 1646) was an English politician who sat in the House of Commons between 1625 and 1646. He supported the Parliamentarian side in the English Civil War.
Marlott was born in Sussex, the son of Thomas Marlott and his wife Dorothy Stapley.
In 1625 Marlott was elected Member of Parliament for New Shoreham and held the seat until 1629 when King Charles decided to rule without parliament for eleven years. In April 1640, he was re-elected MP for New Shoreham in the Short Parliament and again in November 1640 for the Long Parliament and held the seat until his death in 1646. Marlott was absent on a call of the House on 5 February 1644, being on service of the Parliament. He took the Covenant on 27 March 1644.
Marlott died in 1646 and was buried on at Shoreham by Sea on 8 February 1646.