| Tourney Name: | Copa Libertadores de América |
| Year: | 1966 |
| Dates: | February 5 - April 15 |
| Num Teams: | 17 |
| Confederations: | 8 |
| Champion Other: | Peñarol |
| Count: | 3 |
| Second Other: |  River Plate |
| Matches: | 95 |
| Goals: | 283 |
| Top Scorer: | Daniel Onega (17 goals) |
| Prevseason: | 1965 |
| Nextseason: | 1967 |
The 1966 Copa Libertadores de América was the seventh edition of the premier South American club football tournament, organized by CONMEBOL. Colombia and Brazil did not send their representatives. 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.
Colombia did not send a representative due to the disagreements between CONMEBOL and the Colombian football federations. The Brazilians protested the inclusion of the runners-up of each nation and argued that the tournament should be reserved for national champions. 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. Not having any economic incentives, CONMEBOL was forced to allow clubs the freedom of whether they participated or not. This trend will continue for the next 5 editions.
After winning each of their home legs, Peñarol and River Plate required a playoff to break the deadlock. The match was played in the Estadio Nacional of Santiago, Chile. River Plate finished the first half 2-0 and was in cruise control towards its first title. The manyas managed to revert the disadvantage to push this match into extra time. With two more goals, the final score of 2-4 meant that Peñarol became the first three-time winners of the competition. The collapse of River Plate in the second half led the club to being known, even now, as the "gallinas".
| width=125 | Country | width=150 | Team | width=300 | Qualification method |
|---|---|---|---|---|---|
| CONMEBOL (1 berth) | Independiente | 1965 Copa Libertadores winners | |||
| Argentina (2 berths) | Boca Juniors | 1965 Primera División champion | |||
| River Plate | 1965 Primera División runner-up | ||||
(2 berths) | Deportivo Municipal | 1965 Copa Simón Bolívar champion | |||
| Jorge Wilstermann | 1965 Copa Simón Bolívar runner-up | ||||
(2 berths) | Universidad de Chile | 1965 Primera División champion | |||
| Universidad Católica | 1965 Primera División runner-up | ||||
(2 berths) | Emelec | 1965 Campeonato Ecuatoriano champion | |||
| 9 de Octubre | 1965 Campeonato Ecuatoriano runner-up | ||||
 Paraguay(2 berths) | Olimpia | 1965 Primera División champion | |||
| Guaraní | 1965 Primera División runner-up | ||||
(2 berths) | Alianza Lima | 1965 Primera División champion | |||
| Universitario | 1965 Primera División runner-up | ||||
(2 berths) | Peñarol | 1965 Primera División champion | |||
| Nacional | 1965 Primera División runner-up | ||||
(2 berths) | Lara | 1965 Primera División champion | |||
| Deportivo Italia | 1965 Primera División runner-up |
At each stage of the tournament teams receive 2 points for a win, 1 point for a draw, and no points for a loss. If two or more teams are equal on points, the following criteria will be applied to determine the ranking in the group stage:
Sixteen teams were drawn into two groups of six and one group of four. In each group, teams played against each other home-and-away. The top two teams in each group advanced to the Semifinals. Independiente, the title holders, had a bye to the next round.
| width=175 | Team | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| River Plate | 10 | 8 | 1 | 1 | 23 | 8 | +15 | 17 | |||||||||
| Boca Juniors | 10 | 7 | 0 | 3 | 19 | 9 | +10 | 14 | |||||||||
 Universitario | 10 | 4 | 3 | 3 | 10 | 13 | -3 | 11 | |||||||||
 Deportivo Italia | 10 | 4 | 2 | 4 | 15 | 18 | -3 | 10 | |||||||||
| Alianza Lima | 10 | 2 | 0 | 8 | 9 | 16 | -7 | 4 | |||||||||
| Lara | 10 | 1 | 2 | 7 | 5 | 17 | -12 | 4 |
| width=175 | Team | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Universidad Católica | 6 | 2 | 3 | 1 | 9 | 5 | +4 | 7 | |||||||||
| Guaraní | 6 | 2 | 2 | 2 | 9 | 9 | 0 | 6 | |||||||||
| Olimpia | 6 | 2 | 2 | 2 | 7 | 10 | -3 | 6 | |||||||||
| Universidad de Chile | 6 | 1 | 3 | 2 | 6 | 7 | -1 | 5 | |||||||||
| width=175 | Team | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Peñarol | 10 | 8 | 0 | 2 | 20 | 10 | +10 | 16 | |||||||||
| Nacional | 10 | 7 | 1 | 2 | 22 | 10 | +12 | 15 | |||||||||
 Jorge Wilstermann | 10 | 4 | 2 | 4 | 14 | 14 | 0 | 10 | |||||||||
| Deportivo Municipal | 10 | 4 | 1 | 5 | 21 | 22 | -1 | 9 | |||||||||
 Emelec | 10 | 4 | 0 | 6 | 15 | 18 | -3 | 8 | |||||||||
| 9 de Octubre | 10 | 1 | 0 | 9 | 13 | 31 | -18 | 2 | |||||||||
Seven teams were drawn into two groups, one of four and the other of three. In each group, teams played against each other home-and-away. The top team in each group advanced to the Finals.
| width=175 | Team | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | width=20 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| River Plate | 6 | 3 | 2 | 1 | 13 | 8 | +5 | 8 | |||||||||
| Independiente | 6 | 3 | 2 | 1 | 9 | 6 | +3 | 8 | |||||||||
| Boca Juniors | 6 | 2 | 3 | 1 | 7 | 6 | +1 | 7 | |||||||||
| Guaraní | 6 | 0 | 1 | 5 | 5 | 14 | -9 | 1 | |||||||||
See main article: 1966 Copa Libertadores Finals.
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| Pos | Player | Team | Goals | |
|---|---|---|---|---|
| 1 | Daniel Onega | River Plate | 17 | |
| 2 | Pedro Rocha | Peñarol | 10 | |
| align=center rowspan=9 | 3 | Alfredo Hugo Rojas | Boca Juniors | 7 |
| Julio César Morales | Nacional | 7 | ||
| Orlando Virgili | Nacional | 7 | ||
| Agostino Nitti | Deportivo Italia | 7 | ||
| Salomón Moyano | Deportivo Municipal | 7 | ||
| Gerardo González | Olimpia | 7 | ||
| Hugo Lencina | Emelec | 7 | ||
| Cirilo Fernández | 9 de Octubre | 7 | ||
| Ausberto García | Jorge Wilstermann | 7 |
A. The match finished 1-1, but Universitario were declared 0-1 winners as Alianza fielded two ineligible players: Catalá and Cruz.