The Little World Series was renamed the Junior World Series in 1931. The annual match-up between the top teams in the American Association and International League continued through 1962 (except for no series in '35), when the AA folded. When it was re-established in '69, several more Junior World Series were played before the institution died off in '75.  From 1998 to 2000, the Triple-A World Series pitted the IL and Pacific Coast League champs. 

 Results: 
 * 1931 - Rochester Red Wings (IL) def. St. Paul Saints (AA) 5 games to 3 
 * 1932 - Newark Bears (IL) def. Minneapolis Millers (AA) 4 games to 2 
 * 1933 - Columbus (OH) Red Birds (AA) def. Buffalo Bisons (IL) 5 games to 3 
 * 1934 - Columbus (OH) Red Birds (AA) def. Toronto Maple Leafs (IL) 5 games to 4 
 * 1935 - No series 
 * 1936 - Milwaukee Brewers (AA) def. Buffalo Bisons (IL) 4 games to 1 
 * 1937 - Newark Bears IL) def. Columbus (OH) Red Birds (AA) 4 games to 3 
 * 1938 - Kansas City Blues (AA) def. Newark Bears (IL) 4 games to 3 
 * 1939 - Louisville Colonels (AA) def. Rochester Red Wings (IL) 4 games to 3 
 * 1940 - Newark Bears (IL) def. Louisville Colonels (AA) 4 games to 2 
 * 1941 - Columbus (OH) Red Birds (AA) def. Montreal Royals (IL) 4 games to 2 
 * 1942 - Columbus (OH) Red Birds (AA) def. Syracuse Chiefs (IL) 4 games to 1 
 * 1943 - Columbus (OH) Red Birds (AA) def. Syracuse Chiefs (IL) 4m games to 1 
 * 1944 - Baltimore Orioles (IL) def. Louisville Colonels (AA) 4 games to 2 
 * 1945 - Louisville Colonels (AA) def. Newark Bears (IL) 4 games to 2 
 * 1946 - Montreal Royals (IL) def. Louisville Colonels (AA) 4 games to 2 
 * 1947 - Milwaukee Brewers (AA) def. Syracuse Chiefs (IL) 4 games to 3 
 * 1948 - Montreal Royals (IL) def. St. Paul Saints (AA) 4 games to 1 
 * 1949 - Indianapolis Indians (AA) def. Montreal Royals (IL) 4 games to 2 
 * 1950 - Columbus (OH) Red Birds (AA) def. Montreal Royals (IL) 4 games to 2 
 * 1951 - Milwaukee Brewers (AA) def. Montreal Royals (IL) 4 games to 2 
 * 1952 - Rochester Red Wings (IL) def. Kansas City Blues (AA) 4 games to 3 
 * 1953 - Montreal Royals (IL) def. Kansas City Blues (AA) 4 games to 1 
 * 1954 - Louisville Colonels (AA) def. Syracuse Chiefs (IL) 4 games to 2 
 * 1955 - Minneapolis Millers (AA) def. Rochester Red Wings (IL) 4 games to 3 
 * 1956 - Indianapolis Indians (AA) def. Rochester Red Wings (IL) 4 games to 0 
 * 1957 - Denver Bears (AA) def. Buffalo Bisons (IL) 4 games to 1 
 * 1958 - Minneapolis Millers (AA) def. Montreal Royals (IL) 4 games to 0 
 * 1959 - Havana Sugar Kings (IL) def. Minneapolis Millers (AA) 4 games to 3 
 * 1960 - Louisville Colonels (AA) def. Toronto Maple Leafs (IL) 4 games to 2 
 * 1961 - Buffalo Bisons (IL) def. Louisville Colonels (AA) 4 games to 0 
 * 1962 - Atlanta Crackers (IL) def. Louisville Colonels (AA) 4 games to 3 
 * 1970 - Syracuse Chiefs (IL) def. Omaha Royals (AA) 4 games to 1 
 * 1971 - Rochester Red Wings (IL) def. Denver Bears (AA) 4 games to 3 
 * 1972 - Bypassed in favor of World Baseball Classic 
 * 1973 - Pawtucket Red Sox (IL) def. Tulsa Oilers (AA) 4 games o 1 
 * 1975 - Evansville Triplets (AA) def. Tidewater Tides (IL) 4 games to 1