The 1904–05 Federal Amateur Hockey League (FAHL) season lasted from December 31, 1904, until March 3. Teams played an eight-game schedule.
The Ottawa Hockey Club, who officially joined the FAHL prior to the end of the last season, played its first full season in the league. Montreal Le National left the league and joined the rival Canadian Amateur Hockey League (CAHL). Ottawa had negotiated with the CAHL to return, along with the Wanderers joining, but this was turned down. The Ottawa Capitals also left the FAHL.