Paul Janson (11 April 1840 – 19 April 1913) was a Walloon Belgian liberal politician. Born in Herstal, Janson studied philosophy and law at the Université Libre de Bruxelles. From an early age he was a strong supporter of electoral reform and stood on the progressive wing of the Belgian liberal movement. A modern study suggests that only "his visceral rejection of the class struggle" kept him from the burgeoning socialist movement. In his later years he favoured electoral co-operation with the Socialist Party. He was appointed an honorary Minister of State on 14 August 1912.