The 1908 Campeonato Carioca, the third edition of that championship, kicked off on May 3, 1908, and ended on November 1, 1908. It was organized by LMSA (Liga Metropolitana de Sports Athleticos, or Metropolitan Athletic Sports League). Six teams participated. Fluminense won the title for the 3rd time. No teams were relegated.
The tournament would be disputed in a double round-robin format, with the team with the most points winning the title.