Ole Kristian Hallesby (5 August 1879 – 22 November 1961) was a conservative, Norwegian Lutheran theologian, author and educator.

Hallesby grew up as the sixth of eight siblings on a family farm with a father also served as an assistant pastor.

[4][5] An outspoken opponent of the Nazi occupation of Norway, he was arrested and detained at Grini concentration camp for two years (until the end of the war).

[6] In 1953, a radio speech by Hallesby caused a major debate in Norway on the existence of hell.

The bishop of Hamar Kristian Schjelderup was the main spokesperson for the liberal side who argued that the damnation of hell was incompatible with a religion of love.