Arne Ording (7 May 1898 – 26 July 1967) was a Norwegian historian and politician for Mot Dag and the Labour Party.
Ording was born in Kristiania as a son of theology professor Johannes Ording (1869–1929) and Fredrikke Ording (1874–1966). He was a maternal great-grandson of Andreas Hauge, a nephew of educator and politician Fredrik Ording and theologian Hans Nielsen Hauge Ording, a first cousin of actor Jørn Ording and a second cousin of Aake Anker Ording.
He took his examen artium in 1916, and subsequently enrolled at the Royal Frederick University. In 1921 he joined the group around the periodical Mot Dag, and when Mot Dag was formalized as an organization, Ording became one of the prominent members.Mot Dag was a revolutionary socialist group, and had a goal of attracting an elite of intellectuals. Ording was also the chairman of the Mot Dag-affiliated organization Clarté, and edited its periodical of the same name for a period.
He graduated with the cand.philol. degree in 1924, and continued his studies. He had a stay in France from 1926 to 1927, and took the dr.philos. degree in 1930 with the thesis Le Bureau de police du Comité de Salut public. Étude sur la Terreur. In 1936 he issued the book Den første internasjonale. Arbeiderbevegelsens gjennombrudd 1830–1875, about the First International.
The same year, in 1936, Mot Dag was absorbed by the Norwegian Labour Party. Ording edited their periodical Det 20de Århundre together with Finn Moe, and also worked as a commentator in the Norwegian Broadcasting Corporation.