The 1921 VFL season was the 25th season of the Victorian Football League (VFL), the highest-level senior Australian rules football competition in Victoria.

Carlton won the minor premiership by finishing atop the home-and-away ladder with a 13–1–2 win–loss–draw record.

In 1921, the VFL competition consisted of nine teams of 18 on-the-field players each, with no "reserves", although any of the 18 players who had left the playing field for any reason could later resume their place on the field at any time during the match.

Each team played each other twice in a home-and-away season of 18 rounds (i.e., 16 matches and 2 byes).

Once the 18 round home-and-away season had finished, the 1921 VFL Premiers were determined by the specific format and conventions of the amended "Argus system".