Jack McKeon, American baseball player and manager
Jack Aloysius McKeon (; born November 23, 1930), nicknamed "Trader Jack," is an American former Major League Baseball manager and front-office executive.

In 2003, at age 72, he won a World Series as manager of the Florida Marlins. Two full seasons removed from his previous managing job, McKeon had begun the 2003 season in retirement, but on May 11, he was induced to return to uniform to replace Jeff Torborg as the Marlins' skipper. The team was 16–22 and in next-to-last place in the National League East Division. Described upon his hiring by Marlins' general manager Larry Beinfest as a "resurrection specialist," McKeon led the Marlins to a 75–49 win–loss record, a wild card berth, victories over the San Francisco Giants and Chicago Cubs in the National League divisional and championship series playoffs, and then a six-game World Series triumph over the New York Yankees.

He remained at the helm of the Marlins through 2005, then retired at age 74. In 2011, he took over the Marlins on June 20 for a second time as interim manager following the resignation of Edwin Rodríguez and served out the season. In so doing he became, at 80, the second oldest manager in big league history, behind only Connie Mack. He retired again at the end of the season with a career managerial record of 1,051–990 (.515).

McKeon previously managed the Kansas City Royals (1973–1975), Oakland Athletics (parts of both 1977 and 1978), San Diego Padres (1988–1990), and Cincinnati Reds (1997–2000).

From July 7, 1980, through September 22, 1990, he served as the general manager of the Padres, assembling the team which won the 1984 National League pennant, the first in San Diego history.