Copa Libertadores 1973 was won by defending champions Independiente of Argentina after defeating Colo Colo of Chile in a third decisive game.

The third match which ended 2–1 in extra time was necessary after the previous two leg matches ended in draws.

The Venezuelan club teams Deportivo Italia and Deportivo Galicia did not participate in the Copa Libertadores due to internal problems with the Venezuelan Football Federation.

The champions and runners-up of each football association were drawn into the same group along with another football association's participating teams.

Three clubs from Argentina competed as Independiente was champion of the 1972 Copa Libertadores.