The 1920 Argentine Primera División was the 29th season of top-flight football in Argentina. The AFA season began on March 21 and ended in January 1921 while the AAmF began on March 28 and also ended in January 1921.
The tournament started with 17 teams then expanded to 19 when Lanús and Sportivo Almagro (that had previously left the Asociación Argentina) joined the league. Ferro Carril Oeste returned to the league after being relegated 2 years before. Barracas Central debuted in Primera after winning the Primera B (Aam) title last year. Sportivo Buenos Aires also debuted in the top division.