Casey Paul Fossum (born January 6, 1978) is a former professional pitcher. Previously, he played for the Boston Red Sox (2001–2003), Arizona Diamondbacks (2004), Tampa Bay Devil Rays (2005–2007), Detroit Tigers (2008), and New York Mets (2009) of Major League Baseball, and the Hanshin Tigers (2010) of Nippon Professional Baseball. He bats and throws left-handed.