The Midwest League is a Minor League Baseball league established in 1947 and based in the Midwestern United States. A Class A league for most of its history, the league was promoted to High-A as part of Major League Baseball's 2021 reorganization of the minor leagues. The Midwest League began as the Illinois State League (1947–1948) and then became the Mississippi–Ohio Valley League (1949–1955). In 1956, the Mississippi–Ohio Valley League was renamed the Midwest League. The circuit temporarily operated for the 2021 season as the High-A Central before reassuming its original moniker in 2022.