Henrik Jørgen Huitfeldt-Kaas (2 February 1834 – 18 May 1905) was a Norwegian historian and Director-General of the National Archives of Norway (riksarkivar). Huitfeldt-Kaas was born in Christiania (now Oslo, Norway). He was a member of both the Danish noble Huitfeldt and Kaas families. He was descended from Lieutenant-General Henrik Jørgen Huitfeldt and Birgitte Christine Kaas. Originally named Henrik Jørgen Huitfeldt, he adopted the name Huitfeldt-Kaas in 1881 when he gained an inheritance from Det Classenske Fideicommis, a charitable foundation which was founded by Danish industrialist and Major General Johan Frederik Classen who had died in 1792. Professionally he was commonly known as H.J. Huitfeldt-Kaas.