Mexican Southeast League was a Class A League that was based in Mexico.
1964 Campeche, Puerto Mexico, Tabasco, 'Yucatan'
1965 No teams entered or left the league.
1966 Orizaba entered the league.
1967 Cuidad del Carmen and Los Choapas (replacing Villahemosa-Tabasco) entered the league.
1968 Minatitlan entered the league; Orizaba left the league.
1969 Los Choapas replaced by Minatitlan.
1970 Minatitlan and 'Yucatan' left the league.
NOTE 1 - Yucatan played in Merida