| Postseason series | Leagues | Years of existence |
| 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 |
| World Baseball Championship | American Association, International League, Pacific Coast League, Hawaii Islanders (PCL), Latin American All-Stars | 1973 |
| 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 Baseball National Championship Game | International League, Pacific Coast League | 2006–present |