James Thomas Mahoney (born May 26, 1934) is a former Major League Baseball shortstop.

He was signed by the Philadelphia Phillies before the 1953 season and played for the Boston Red Sox (1959), Washington Senators (1961), Cleveland Indians (1962) and Houston Astros (1965).

The native of Englewood, New Jersey, threw and batted right-handed, stood 6 feet (1.8 m) tall and weighed 175 pounds (79 kg) during his active career.

Mahoney was the first player to appear as a pinch runner in modern Washington Senators history.

On April 10, 1961, in the bottom of the ninth inning, he entered the game for second baseman Danny O'Connell, who had singled with one out.