John James Jachym (May 9, 1918 – May 10, 2005) was an American businessman, philanthropist, and sportsman. He was briefly (from December 23, 1949, through June 22, 1950) a club owner in Major League Baseball as the second largest shareholder in the Washington Senators of the American League. Later in his career, he was active in Republican Party politics and an important figure in (and a rare honorary member of) the Professional Golfers' Association.