Born in La Corne, Quebec (Abitibi-Témiscamingue district), Champetier became a full-time writer after working in electrochemistry.

Champetier's first published work, Le chemin des fleurs, appeared in Quebec science-fiction and fantasy magazine Solaris in 1981.

In 1987, Champetier became a literary critic in the publication L'année de la science-fiction et du fantastique québécois (Quebec Science Fiction and Fantasy Annual).

In 1996, Champetier was honoured at the Salon du livre de l'Abitibi-Témiscaminque, for which he had been previously in charge of programming in 1991.

Champetier's 1997 novel La peau blanche was adapted into a 2004 film by Daniel Roby which was released in English as White Skin.