Ansgar Eugène Olaussen (27 December 1887 – 22 January 1962) was a Norwegian newspaper editor, educated as a typographer, and politician. As a politician he started in Norges Socialdemokratiske Ungdomsforbund, and notably edited Klassekampen from 1911 to 1921. For the Labour Party he was county leader, central board member and MP for slightly more than a year, until he joined the Communist Party in 1923. Some years after finishing his sole term as an MP for the Communists, he shifted to the far right and associated himself with Nazism during the Second World War.
He was born in Tønsberg as a son of Hannibal Olaussen (1848–1916) and Bella Sophie Johansen (1852–1918). His father was an immigrant from Tanum, Sweden, and was a bookbinder by profession, like Eugène's older sister Anna Catharina. The family later lived in Moss. Eugène Olaussen later settled in Hokksund.
He started his working career at the age of 13, and after some years as a laborer he learned the typographer's trade. His apprenticeship was spent in newspapers like Moss Avis and Jarlsberg. In 1907 he became editor-in-chief of Ung-Socialisten, and was a central board member of the Norges Socialdemokratiske Ungdomsforbund. From 1911 to 1921 he edited the publication of NSU, Klassekampen. He recruited Nikolay Bukharin and Karl Radek to write in the newspaper, and gained a personal acquaintance with Vladimir Lenin.