Michael Jack Schmidt is an American former professional baseball third baseman who played his entire 18-season career in Major League Baseball (MLB) for the Philadelphia Phillies. Schmidt was a 12-time All-Star and a three-time winner of the National League (NL) Most Valuable Player award (MVP), and he was known for his combination of power hitting and strong defense. As a hitter, he compiled 548 home runs and 1,595 runs batted in (RBIs), and led the NL in home runs eight times and in RBIs four times. As a fielder, Schmidt won the National League Gold Glove Award for third basemen ten times. Schmidt was elected to the Baseball Hall of Fame in 1995 and is widely considered to be the greatest third baseman in baseball history.

A third baseman, abbreviated 3B, is the player in baseball or softball whose responsibility is to defend the area nearest to third base — the third of four bases a baserunner must touch in succession to score a run. In the scoring system used to record defensive plays, the third baseman is assigned the number 5.