William Marchant
William Marchant may refer to:
- William Marchant (playwright), American playwright and screenwriter
- William Sydney Marchant, British colonial administrator
- William Marchant (loyalist), Northern Irish loyalist and volunteer in the Ulster Volunteer Force
- William Lavington Marchant, An Australian Pastoralist
- William Marchant (Rhode Island), a Justice of the Rhode Island Supreme Court from 1808 to 1810