Sean McDermott (born March 21, 1974) is an American football coach who is the head coach of the Buffalo Bills of the National Football League (NFL).
McDermott originally joined the Philadelphia Eagles in 1998 as a scouting administrative coordinator, a position he held until being promoted to assistant to the head coach in 1999. He then became defensive quality control coach and later assistant defensive backs coach. In 2003, he replaced Steve Spagnuolo as defensive backs coach, as Spagnuolo was assigned linebackers coach. In 2004, McDermott saw both of his starting safeties (Brian Dawkins and Michael Lewis) earn Pro Bowl berths for the first time in team history. Under McDermott's watch, Dawkins went on to earn two more Pro Bowl berths following the 2005 and 2006 seasons.