William M. Anderson (born 12 March 1948) is an Irish film editor who was nominated for the BAFTA Award for Best Editing for the film Dead Poets Society (1989). He has had an extended, notable association with the director Peter Weir, beginning with the film Gallipoli (1981), including Dead Poets Society, and continuing through The Truman Show (1998). Lee Smith co-edited The Truman Show, and was sole editor on Weir's next film, Master and Commander: The Far Side of the World (2003). Anderson was born in Belfast, Northern Ireland.