Alliance Atlantis Communications Inc. (formerly traded as TSX:AAC) was a Toronto-based media company that operated primarily as a specialty service operator in Canada. Alliance Atlantis also had offices in Halifax, Los Angeles, London, Dublin, Madrid, Barcelona, Shannon and Sydney.

Alliance Atlantis was acquired by Canwest Global Communications and an affiliate of Goldman Sachs in 2007. The movie business now operates independently as Alliance Films, headquartered in Montreal, and the international television distribution businesses is now owned by Echo Bridge Entertainment.

All of the former Alliance Atlantis specialty networks are now owned by Shaw Communications through its Shaw Media Division (formely CW Media) as of October 27, 2010.

Alliance Atlantis was formed in 1998 from the merger of two former production companies, Alliance Communications and Atlantis Communications, both founded in 1985. The merger was a bit unusual in that the head of Atlantis, Michael MacMillan, became CEO of the new firm even though Atlantis was the smaller partner in the transaction^{[citation needed]}; Alliance's CEO, Robert Lantos, was specifically interested in moving back into a production role^{[citation needed]}. As President and Board Director of the subsequent combined Alliance Atlantis, Lewis Rose was responsible for leading the teams which arranged the merger financing of $545 million and which achieved in excess of $20 million in savings and synergies from the combination of the two companies in the year following the merger. (The merger was also parodied on Made in Canada, when that show's Pyramid Productions merged with a company called Prodigy.)