The 1991 Campeonato Nacional, was the 59th season of top-flight football in Chile.
Colo-Colo won its eighteenth title following a 0–0 away draw against Coquimbo Unido on 18 December.
Coquimbo Unido, as runner-up, and Universidad Católica, as Liguilla winners, also qualified for the next Copa Libertadores .
* Qualified as "Best Loser" Universidad Católica also qualified for the 1992 Copa Libertadores Everton and Universidad de Chile will play in the 1992 Primera División