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. Their second consecutive title made Independiente the first team in the tournament's history to win four titles.

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.

Country	Team	Qualification method
CONMEBOL (1 berth)	Independiente	1972 Copa Libertadores champion
Argentina (2 berths)	San Lorenzo	1972 Nacional champion
	River Plate	1972 Nacional runner-up
Bolivia (2 berths)	Jorge Wilstermann	1972 Primera División champion
	Oriente Petrolero	1972 Primera División runner-up
Brazil (2 berths)	Palmeiras	1972 Campeonato Brasileiro Série A champion
	Botafogo	1972 Campeonato Brasileiro Série A runner-up
Chile (2 berths)	Colo-Colo	1972 Primera División champion
	Unión Española	1972 Primera División runner-up
Colombia (2 berths)	Millonarios	1972 Campeonato Profesional champion
	Deportivo Cali	1972 Campeonato Profesional runner-up
Ecuador (2 berths)	Emelec	1972 Campeonato Ecuatoriano champion
	El Nacional	1972 Campeonato Ecuatoriano runner-up
Paraguay (2 berths)	Cerro Porteño	1972 Primera División champion
	Olimpia	1972 Primera División runner-up
Peru (2 berths)	Sporting Cristal	1972 Primera División champion
	Universitario	1972 Primera División runner-up
Uruguay (2 berths)	Nacional	1972 Primera División champion
	Peñarol	1972 Primera División runner-up

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. They entered the tournament in the Semifinals.

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification		SLO	WIL	RIV	ORI
1	San Lorenzo	6	5	0	1	15	1	+14	10	Semifinals		—	3–0	1–0	4–0
2	Jorge Wilstermann	6	3	1	2	6	8	−2	7			1–0	—	1–0	1–0
3	River Plate	6	2	1	3	12	10	+2	5			0–4	2–2	—	7–1
4	Oriente Petrolero	6	1	0	5	5	19	−14	2			0–3	3–1	1–3	—

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification		BOT	PAL	NAC	PEÑ
1	Botafogo	6	4	1	1	15	9	+6	9	Semifinals		—	2–0	3–2	4–1
2	Palmeiras	6	4	1	1	10	6	+4	9			3–2	—	1–1	2–0
3	Nacional	6	1	2	3	8	9	−1	4			1–2	1–2	—	2–0
4	Peñarol	6	0	2	4	4	13	−9	2			2–2	0–2	1–1	—

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification		COL	EME	NAC	UES
1	Colo-Colo	6	3	2	1	16	4	+12	8	Semifinals		—	5–1	5–1	5–0
2	Emelec	6	3	1	2	6	7	−1	7			1–0	—	2–0	1–0
3	El Nacional	6	2	1	3	5	10	−5	5			1–1	1–0	—	1–0
4	Unión Española	6	1	2	3	3	9	−6	4			0–0	1–1	2–1	—

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification		MIL	CAL
1	Millonarios	2	1	1	0	6	2	+4	3	Semifinals		—	6–2
2	Deportivo Cali	2	0	1	1	2	6	−4	1			0–0	—

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification		CER	OLI	SCR	UNI
1	Cerro Porteño	6	4	1	1	14	5	+9	9	Semifinals		—	4–2	5–0	1–0
2	Olimpia	6	3	0	3	9	9	0	6			2–1	—	1–0	3–1
3	Sporting Cristal	6	2	2	2	5	9	−4	6			1–1	1–0	—	2–2
4	Universitario	6	1	1	4	5	10	−5	3			0–2	2–1	0–1	—

• The five previous group leaders formed two new groups of three which included the 1972 Copa Libertadores defending champion Independiente.

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification or relegation		IND	SLO	MIL
1	Independiente	4	2	1	1	5	3	+2	5	Qualified to the Final		—	1–0	2–0
2	San Lorenzo	4	1	2	1	4	3	+1	4			2–2	—	2–0
3	Millonarios	4	1	1	2	1	4	−3	3			1–0	0–0	—

Pos	Team	Pld	W	D	L	GF	GA	GD	Pts	Qualification or relegation		COL	CER	BOT
1	Colo-Colo	4	2	1	1	10	9	+1	5	Qualified to the Final		—	4–0	3–3
2	Cerro Porteño	4	2	0	2	8	9	−1	4			5–1	—	3–2
3	Botafogo	4	1	1	2	8	8	0	3			1–2	2–0	—

Independiente v Colo-Colo

22 May 1973

Independiente

1–1

Colo-Colo

Avellaneda

Colo-Colo v Independiente

29 May 1973

Colo-Colo

0–0

Independiente

Santiago

Independiente v Colo-Colo

6 June 1973

Independiente

2–1

Colo-Colo

Montevideo

Copa Libertadores 1973 Winners
Independiente Fourth Title