Gérard Klein, also known as Gilles d'Argyre, is a French science fiction writer born in 1937 with sociological training.

He is the editor of the prestigious science fiction imprint Ailleurs et Demain published by Robert Laffont and of the Livre de Poche science-fiction imprint.

In his novella Les virus ne parlent pas ("The viruses do not speak"), he imagines that viruses have created all living beings in the same fashion that human beings have created computers, and for the same reason: to improve their efficiency.

Gérard Klein used the Gilles d'Argyre pseudonym to sign his novels published by Editions Fleuve Noir in their Anticipation imprint.

Several of his novels were translated by DAW Books in the United States.