Born November 19, 1958, in Longeville-les-Metz, France, but considers Toulouse, France, to be his hometown. Married to the former Laurence Boulanger. They have two children. He enjoys racquet sports, skill games, canyoning, skiing, and flying activities such as boomerang, frisbee, kites. His and her parents reside near Paris, France.
In 1991, he trained in Star City, Moscow, on the Soyuz and Mir systems. In 1992, he joined the astronaut corps of the European Space Agency (ESA) at the European Astronaut Center EAC in Cologne.

Clervoy was detached to the NASA Johnson Space Center/Houston in August 1992 to gain the Space Shuttle mission specialist qualifications. In between his space flights, Clervoy was assigned as flight software verification lead in the Shuttle Avionics Integration Laboratory (SAIL) and as robotics display design lead for Shuttle and Station. After his third spaceflight, he provided collateral duties in the NASA-JSC Astronaut Office on International Space Station display integration lead within the Space Station Operations Branch.