Henri Ghéon, born Henri Vangeon in Bray-sur-Seine, Seine-et-Marne, was a French playwright, novelist, poet and critic.

Brought up by a devout Roman Catholic mother, he lost his faith in his early teens, while still at the Lycée in Sens. Among the factors that brought this about, one stood out in his own mind: at school religion was taught without life or understanding. Ghéon did not miss it. As F. J. Sheed says, "His was a happy atheism." He replaced Catholicism with a semi-pagan cult of beauty in all its forms — nature, literature, music, painting.

He moved to Paris in 1893 to study medicine. Around the same time, he started to write poetry, along with his colleagues Francis Jammes and Stéphane Mallarmé. He also published avant garde criticism. In 1887 he met André Gide, who became his literary guide and friend for twenty years. Ghéon, writes Gide's biographer Alan Sheridan, "was Gide's closest friend and companion on innumerable homosexual exploits." Ghėon actually drafted a militant text in favour of homosexuality, La Vie secrète de Guillaume Arnoult, which was one of the inspirations for Gide's Corydon. In 1909 they were founding members of the Nouvelle Revue Française (NRF). Ghéon also painted, studied music and travelled widely.

It was the sceptic Gide who occasioned the first cracks in Ghéon's paganism when he invited him to visit Florence with him in 1912. There Ghéon discovered the religious art of Giotto and Fra Angelico and was overwhelmed to the point of shedding tears. "At St Mark's," he wrote, "with Christ dying on the cross and the Virgin waiting for the angel in a bare and silent corridor..., even our senses had a soul. Art had transported me before, but never so high."

He served as an army doctor in the First World War. During this period he regained his Catholic faith, as described in his work L'homme né de la guerre (The Man Born from the War). His conversion was bound up with a devoutly Catholic naval officer, Pierre Dominique Dupouey, whom he met only three times in the space of a few weeks, but who impressed him greatly. It was again Gide who was the occasion for this fateful encounter: when Ghéon left for the Belgian front, Gide urged him to try to find Dupouey, who had once been his disciple and with whom he still corresponded. On Holy Saturday, 1915, Dupouey was killed in action on the Yser. By Christmas, Ghéon had returned to the Catholic faith.

He founded the "Compagnons de Notre Dame" (Companions of Our Lady), a sort of amateur theatre confraternity of young people, for which he wrote over 60 plays, usually on episodes from the Gospel or the lives of the saints. Ghéon's plays had clear similarities with the medieval mystery and miracle plays. The Companions of Our Lady performed with success in Paris and throughout France, as well as in Belgium, Holland and Switzerland, and Ghéon was awarded a prize for his work by the Académie française. He also wrote poems, saints' biographies, and novels, among them a three-part work, Les Jeux de l'enfer et du ciel (Games of Hell and Heaven), centred on the Curè d'Ars.

Ghéon died of cancer in a Paris clinic on 13 June 1944, a week after the Allied landing in Normandy and six days after the opening of his most recent play, Saint Gilles.