The 1977 Copa Libertadores was the 18th edition of CONMEBOL's top club tournament. The tournament was won by Boca Juniors after defeating defending champions Cruzeiro for their first Copa Libertadores title.
Groups are organized by countries, with two teams from two countries composing a group. The top team from each group moves onto the next round (semi-finals). Defending champions Cruzeiro received a bye to the second round.
The winner is determined by points (i.e., whoever wins the most of two games); goal difference or aggregate score is not used. If the points are tied after two games, a single-game playoff at a neutral sight will be played. If the game is tied after regulation, a penalty shootout will determine the winner.