The Montreal Shamrocks were an amateur, later professional, and then amateur again men's ice hockey club in existence from 1886 to 1924, based in Montreal, Quebec, Canada. They were spun off from the Montreal Shamrocks lacrosse club. Starting off as an independent club and briefly playing in the AHAC, the team became a permanent fixture in the early amateur leagues, when in 1895 they merged with the Montreal Crystals and replaced them midway through the 1895 season in the AHAC. The club eventually went professional and played one season in the National Hockey Association (NHA), the predecessor of today's National Hockey League. Afterwards, with the cost of professionalism being too expensive, the team reverted to an amateur club and played into the 1920s in various amateur leagues. Their greatest success came when they won back to back Stanley Cups at the turn of the century in 1899 and 1900.

The Amateur Hockey Association of Canada (AHAC) was an amateur men's ice hockey league founded on 8 December 1886, in existence until 1898. It was the second ice hockey league organized in Canada, after one in Kingston, Ontario started in 1883. It was organized to provide a longer season to determine the Canadian champion. Prior to its founding, the Canadian championship was determined in a tournament in Montreal. It is the first championship ice hockey league.