Donald John McMahon
- Bats Right, Throws Right
- Height 6' 2", Weight 222 lb.
- High School Erasmus Hall High School
- Debut June 30, 1957
- Final Game June 29, 1974
- Born January 4, 1930 in Brooklyn, NY USA
- Died July 22, 1987 in Los Angeles, CA USA
McMahon was on the military list from May 30, 1951 to May 17, 1953, missing the entire 1952 season.
He collected a base hit at age 43 in his final major league at bat, an RBI single off Dave Tomlin. He also was the winning pitcher in that game on September 28, 1973. He had retired before the season and was serving as the San Francisco Giants' pitching coach when he was pressed into service that season because of a depleted bullpen. This happened again in 1974.
McMahon served as a coach for the Giants (1972-1975), Minnesota Twins (1976-1978), Giants again (1980-1982), and Cleveland Indians (1983-1985). He was serving as a special assignment scout for the Los Angeles Dodgers when he suffered a fatal heart attack while throwing batting practice before a game.
- NL All-Star (1958)
- NL Saves Leader (1959)
- Won two World Series with the Milwaukee Braves (1957) and the Detroit Tigers (1968)
- John Vorperian: "Don McMahon", in Gregory H. Wolf, ed.: Thar's Joy in Braveland: The 1957 Milwaukee Braves, SABR, Phoenix, AZ, 2014, pp. 130-134. ISBN 978-1933599717