The 1905 Canadian Amateur Hockey League (CAHL) season was the seventh and final season of the league. Teams played a ten-game schedule. This year saw the addition of two teams, Montreal Westmount and Montreal Nationals. Montreal Nationals had previously been in the FAHL. Montreal Victorias won the league championship with a record of 9–1.

The Canadian Amateur Hockey League (CAHL) was an early men's amateur hockey league founded in 1898, replacing the organization that was formerly the Amateur Hockey Association of Canada (AHAC) before the 1898–99 season. The league existed for seven seasons, folding in 1905 and was itself replaced by the Eastern Canada Amateur Hockey Association (ECAHA). Formed because of a dispute between teams of the AHAC, it further developed the sport in its transition to professional, with a growing focus on revenues. The CAHL itself would fold over a dispute, leading to the new ECAHA league.