The 1966 Copa Libertadores de América was the seventh edition of the premier South American club football tournament, organized by CONMEBOL.

This edition became the first club competition of the world to include not just the champions but also the runners-up of each of its participating association.

Despite the fact that Colombian and Brazilian clubs did not participate, this tournament saw a record 95 matches being played out to determine the year's champion.

That led them to become denatured and the powers reserved only for the champions, in addition to the priority order they gave their interstate tournaments and the many unattractive encounters-to-come against teams from the "Pacific", the Brazilian clubs opted for tours around the world instead as they were seen more economically rewarding.

After winning each of their home legs, Peñarol and River Plate required a playoff to break the deadlock.