Since the 1902 foundation of the National Association of Professional Baseball Leagues, commonly known as Minor League Baseball, various leagues have held interleague series in the postseason between their champions or other qualifiers.
SeriesLeaguesYears New England Championship Connecticut League, New England League 1903, 1905–1906 Little World Series American Association, International League 1904, 1906–1907, 1917, 1920–1931 Iowa State Series Iowa State League, Three-I League, Western League 1905 Dixie Championship South Atlantic League, Virginia League 1906 Midwest Championship Iowa State League, Wisconsin State League 1907 Carolina Championship Carolina Association, Eastern Carolina League 1909 Dixie Championship South Atlantic League, Southern Association 1909, 1919 New York versus Pennsylvania Series New York State League, Tri-State League 1909 Kansas versus Nebraska Series Eastern Kansas League, M.I.N.K. League 1910 Northern Championship Minnesota–Wisconsin League, Wisconsin–Illinois League 1910 Carolina versus Virginia Series Carolina Association, Virginia League 1911 Class D Series Blue Grass League, Kentucky–Illinois–Tennessee League 1912 Western Championship American Association, Western League 1912 Virginia Series Appalachian League, Virginia League 1912 Class B Championship Series Eastern Association, New England League 1913, 1914 Michigan State Championship Michigan State League, Southern Michigan Association 1913 Minor League Championship American Association, Western League 1913, 1916 Minor League Championship American Association, Southern Association, Western League 1914 Virginia-North Carolina Series North Carolina State League, Virginia League 1914–1915 Junior World Series American Association, Pacific Coast League 1919 Dixie Series Southern Association, Texas League 1920–1958 Border Series Texas–Oklahoma League, Western Association 1921 Class B Championship Series Central League, Michigan–Ontario League 1921 Class D Series Southwestern League, Western Association 1921 Little World Series Tune-up Eastern League, International League 1922–1925 Class A Series Western League, Southern Association 1922 Class B Southern Championship South Atlantic League, Virginia League 1922–1923 Five-State Championship Blue Ridge League, Eastern Shore League 1922–1927 Lone Star Series East Texas League, Texas Association 1924, 1926 Class AA Series American Association, Pacific Coast League 1924 San Francisco-Louisville Series American Association, Pacific Coast League 1925 Southern Championship South Atlantic League, Virginia League 1925–1927 Northern Championship Three-I League, Michigan State League 1926 Mid-Western Championship Three-I League, Western League 1926 Eastern Championship New York–Penn League, New England League 1926 Eastern Championship New York–Penn League, Eastern League 1926, 1930 Class B Championship New York–Penn League, Virginia League 1927 Eastern Championship Eastern League, International League 1927, 1929 Southern Championship Southeastern League, South Atlantic League 1927–1928, 1930 Texas Class D Championship Lone Star League, West Texas League 1928 Tri-State Series Middle Atlantic League, Blue Ridge League 1928–1929 Eastern Series New England League, Eastern League 1929 Midwest Championship Central League, Three-I League 1929–1930 Junior World Series American Association, International League 1932–1934, 1936–1962, 1970–1971, 1973–1974 Midwest Series Western League, Mississippi Valley League 1933 Pan American Association Mexican League, Texas League 1959–1961 Dixie Series Southern League, Texas League 1967 Kodak World Baseball Classic American Association, International League, Pacific Coast League, Hawaii Islanders (PCL), Caribbean All-Stars 1972 Triple-A World Series American Association, International League, Pacific Coast League 1983 Triple-A Classic American Association, International League 1988–1991 Triple-A World Series International League, Pacific Coast League 1998–2000 Triple-A National Championship Game International League, Pacific Coast League 2006–2019, 2022–present