Robert Thomas (28 September 1927 in Gap, Hautes-Alpes – 3 January 1989) was a French writer, actor and film director. As a writer, almost from the beginning, he was fascinated by a curious genre that he helped invent: the comédie policière or comedy thriller, of which Eight Women is an example.

In 1960, Thomas had a hit with Man Trap, a humorous murder mystery which was an overnight success in Paris. Alfred Hitchcock bought the rights and the play established Thomas as a writer of psychological crime dramas with a distinctively Gallic comic twist. The following year the second outing of Eight Women was far more successful as it won the Hachette Prix du Quai des Orfevres for Best Play in 1961.