Jean Denis (10 November 1902 – 10 March 1992) was a Belgian politician and writer. Through his written work he was the chief ideologue of the Rexist movement.

A native of Chastre-Villeroux-Blanmont in Walloon Brabant, Denis was educated to doctorate level.^[1] He first became involved in politics with the radical Catholic movements, serving as secretary to Monsignor Louis Picard.^[1] Léon Degrelle had also been a member of Picard's Action Catholique de la Jeunesse Belge and it was that movement's publishing house, Éditions Rex, that inspired the name of Rexism.^[2] As such Denis was almost inevitably drawn to Rexism and he served as a deputy for Namur between 1936 and 1939.^[3]

Denis two main books were Principes Rexistes and Bases Doctrinales de Rex, both published in 1936. Within these books he argued that Rex was more of a popular movement than a political party and endorsed a policy that sought to restore dignity to Belgium through a new hierarchical state. As such he demonstrated an influence of Integralismo Lusitano, which held similar views with regards to Portugal, on Rexist thought.^[3]

Under the Nazi German occupation Denis collaborated with the occupiers and wrote regularly for Le Pays Réel.^[3] He was imprisoned after the war for his activity but his fairly minor involvement saw him released in 1951. He settled in Dion-le-Val, Chaumont-Gistoux following his release and disappeared into obscurity.^[3]