Alfred Manuel "Billy" Martin Jr. (May 16, 1928 – December 25, 1989) was an American Major League Baseball (MLB) second baseman and manager, who, in addition to leading other teams, was five times the manager of the New York Yankees. First known as a scrappy infielder who made considerable contributions to the championship Yankee teams of the 1950s, he then built a reputation as a manager who would initially make bad teams good, before ultimately being fired amid dysfunction. In each of his stints with the Yankees he managed them to winning records before being fired by team owner George Steinbrenner or resigning under fire.
Martin was born in a working-class section of Berkeley, California. His skill as a baseball player gave him a route out of his home town. Signed by the Pacific Coast League Oakland Oaks, Martin learned much from Casey Stengel, the man who would manage him both in Oakland and in New York, with whom he enjoyed a close relationship.