The Halifax-class frigate, also referred to as the City class, is a class of multi-role patrol frigates that have served the Royal Canadian Navy since 1992. The class is the outcome of the Canadian Patrol Frigate Project, which dates to the mid-1970s. HMCS Halifax was the first of an eventual twelve Canadian-designed and Canadian-built vessels which combine traditional anti-submarine capabilities with systems to deal with surface and air threats as well. Ships of the class are named after capital cities of Canadian provinces, the capital of Canada, Ottawa, and the major cities of Calgary, Montreal, and Vancouver.

A frigate is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied.