John Louis Blatnik (March 10, 1921 – January 21, 2004) was an American professional baseball outfielder who played in Major League Baseball (MLB) from 1948 through 1950 for the Philadelphia Phillies and St. Louis Cardinals. Listed at 6 ft (1.8 m), 195 lb (88 kg), Blatnik batted and threw right-handed. In a three-season Major League career, Blatnik was a .253 hitter, with 113 hits, six home runs and 46 runs batted in (RBI) in 138 games, including 59 runs, 27 double, eight triples, three stolen bases, and a .317 on-base percentage.