The Anzac class is a ship class of ten frigates; eight operated by the Royal Australian Navy (RAN) and two operated by the Royal New Zealand Navy (RNZN). During the 1980s, the RAN began plans to replace the River-class destroyer escorts with a mid-capability patrol frigate and settled on the idea of modifying a proven German design for Australian conditions. Around the same time, the RNZN was seeking to replace their Leander-class frigates while maintaining blue-water capabilities. A souring of relations between New Zealand and the United States of America in relation to New Zealand's nuclear-free zone and the ANZUS security treaty prompted New Zealand to seek improved ties with other nations, particularly Australia. As both nations were seeking warships of similar capabilities, the decision was made in 1987 to collaborate on their acquisition. The project name is taken from the Australian and New Zealand Army Corps of the First World War.

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