John Albert Schmitz (November 27, 1920 – October 1, 2011) was an American Major League Baseball pitcher who worked in 366 games over 13 seasons as a member of the Chicago Cubs, Brooklyn Dodgers, New York Yankees, Cincinnati Reds, Washington Senators, Boston Red Sox and the Baltimore Orioles between 1941 and 1956.

His career was interrupted from 1943 through 1945 by United States Navy service in the Pacific theatre of World War II.

Originally signed by the Cleveland Indians in 1938, Schmitz was obtained by the Chicago Cubs from the Milwaukee Brewers of the American Association as part of a minor league working agreement.

Schmitz pitched marvelously in the short stint that would be his first major league season: in five games—including three starts—he went 2–0 with a 1.31 earned run average, and one complete game.

In 1942, Schmitz posted a solid 3.43 ERA despite a mediocre 3–7 record with the Cubs (who as a team went 68–86 that year).

Schmitz' 1947 season was fairly disappointing—he posted a record of 13–18, leading the league in walks.

It was this subpar performance that prompted a trade by the Cubs to the Brooklyn Dodgers (a team he'd won 18 games against) on June 15, 1951.

Schmitz was sent from the Cubs along with Andy Pafko, Wayne Terwilliger and Rube Walker, to the Dodgers for Bruce Edwards, Joe Hatten, Eddie Miksis and Gene Hermanski.

He ended up posting a 3.60 ERA in five games with them before being traded with Jim Greengrass, Bob Marquis and Ernie Nevel to the Cincinnati Reds for Ewell Blackwell.

In the 1955 offseason, Schmitz was traded by the Senators with Bob Porterfield, Tom Umphlett and Mickey Vernon to the Boston Red Sox for Karl Olson, Dick Brodowski, Tex Clevenger, Neil Chrisley and Al Curtis, a minor leaguer.

He ended up appearing in only two games with the Red Sox in 1956 before being purchased by the Baltimore Orioles.