Thomas James Lawless (born December 19, 1956) was a Major League Baseball player between 1982 and 1990, playing for the Cincinnati Reds, Montreal Expos, St. Louis Cardinals, and Toronto Blue Jays.

Although just a fringe, part-time player throughout his career, Lawless was involved in a number of dramatic and historic moments. Lawless became famous in 1984 when he became the only player ever traded for the great Pete Rose. Lawless is also remembered for his dramatic game-winning home run in Game 4 of the 1987 World Series. Then, in 1989, while with the Toronto Blue Jays, Lawless's ninth inning single prevented Mark Langston from pitching a no-hitter.

A fast runner and highly skilled baserunner, Lawless struggled to hit major league pitching and retired in 1990. He entered the coaching ranks and has become a successful minor league manager, managing several teams in the Class A Midwest league. He is known for an aggressive managing style, calling for many stolen bases and sacrifice bunts.