Marcel Allain (1885-1970) was a French writer mostly remembered today for his co-creation with Pierre Souvestre of the fictional arch-villain and master criminal Fantômas.

The son of a Parisian bourgeois family, Allain studied law before becoming a journalist. He then became the assistant of Souvestre, who was already a well-known figure in literary circles. In 1909, the two men published their first novel, Le Rour. Investigating Magistrate Germain Fuselier, later to become a recurring character in the Fantômas series, appears in the novel.

Then, in February 1911, Allain and Souvestre embarked upon the Fantômas book series at the request of publisher Arthème Fayard, who wanted to create a new monthly pulp magazine. The success was immediate and lasting.

After Souvestre’s death in February 1914, Allain continued the Fantômas saga alone, then launched several other series, such as Tigris, Fatala, Miss Téria and Férocias, but none garnered the same popularity as Fantômas.