Sean Casey is an American first baseman on the Boston Red Sox.

Casey began his career in Cleveland, but had his breakout season in 1999 with the Cincinnati Reds. He hit 25 HRs and 99 RBIs that season and was selected to the NL All Stars. He was dealt to Pittsburgh in 2006, but spent most of the season on the DL. He was traded to Detroit at the deadline, and was one of the best assets at the plate for the Tigers in the playoffs. In 2008, Casey signed with the Red Sox, and has spent most of the season as a part time utility player, filling in when other starters have been injured.