The Diocese of Copenhagen is a Latin Church ecclesiastical territory or diocese of the Catholic Church named after its episcopal see, the Danish national capital, Copenhagen and covers all Denmark.

The diocese also covers two Danish overseas possessions, the Faroe Islands and Greenland.

The Diocese of Copenhagen is exempt immediately to the Holy See.

Following the Protestant Reformation in Denmark, a Catholic mission was first reestablished in Denmark on August 7, 1868 as the Vicariate Apostolic of the Northern Missions.

Only on April 29, 1953 was it promoted as the regular, post-missionary Diocese of Copenhagen.