Steven Scott Sinclair (born August 2, 1971 in Victoria, British Columbia) is a former pitcher for the Toronto Blue Jays and Seattle Mariners.
Sinclair made his major league debut for the Blue Jays on April 25, 1998, against the Chicago White Sox and pitched in 24 games that season. On July 28, 1999, he was traded to the Mariners with Tom Davey in exchange for David Segui. Sinclair currently holds the records for saves by a left handed reliever (15) while playing in the Venezuelan Winter League for the Cardenales de Lara. He is the cousin of All-Star and 2006 American League MVP Justin Morneau.