John Thaddeus Ostrowski
- Bats Right, Throws Right
- Height 5' 10½", Weight 170 lb.
- High School Tilden High School
- Debut September 24, 1943
- Final Game October 1, 1950
- Born October 17, 1917 in Chicago, IL USA
- Died November 13, 1992 in Chicago, IL USA
Johnny Ostrowski grew up in Chicago, IL and played baseball at Tilden High School. He began his pro career in 1938 and played several years in the minors, notably as a star third baseman for the Los Angeles Angels, with whom he led the Pacific Coast League with 21 homers in 1943. He was called up the the majors for several cups of coffee with the Chicago Cubs from 1943 to 1946 but saw little playing time behind Stan Hack. In 1948, he appeared in one game with the Boston Red Sox after being selected from the Cubs in the 1947 Rule V Draft but was eventually returned to the Cubs.
In 1949, Ostrowski was traded across town to the Chicago White Sox, becoming one of only a few Chicago natives to play for both hometown teams. The Sox sent him to the Washington Senators the following year, but after being placed on waivers by the Senators, he returned to the Sox and played in his final big league game with the club on October 1, 1950.
After his baseball career, Ostrowski was a truck driver for Waste Management. He died at age 75 in 1992.