Birger Kristian Eriksen (17 November 1875 – 16 July 1958) was a Norwegian military officer (with the rank of Oberst) who was instrumental in stopping the first wave of Gruppe 5 of the German invasion force outside Oslo.

He gained lasting recognition for ordering the fortress under his command to open fire on the vanguard forces of Operation Weserübung, sinking the 16,000-ton heavy cruiser Blücher.

Following a private initiative and the formation of a committee to honour him, Eriksen's ashes were exhumed on 4 October 1977 and moved to the Vår Frelsers gravlund cemetery in Oslo.

[12] The final recognition of Eriksen's efforts, and rebuttal of the early post-war criticisms of some of his actions, took place during the celebrations of the 50th anniversary of the end of the Second World War.

On 6 May 1995 King Harald V unveiled a statue of Eriksen[14] on the Borggården square at Oscarsborg's Main Fort, cementing the Colonel's position amongst the foremost Norwegian leaders of the Second World War.