HDMS Nordkaperen (S321) was a Narhvalen-class submarine of the Royal Danish Navy. She was built to the German Type 205 design at the naval dockyard in Copenhagen where she was laid down on 4 March 1966. She was launched on 18 December 1969, and was commissioned into the Royal Danish Navy on 22 December 1970. In 1994, Nordkaperen and sister ship Narhvalen were modified to bring their technical performance more in line with the Royal Danish Navy's newer Tumleren class. Nordkaperen was decommissioned on 2 February 2004.