He founded the Centre de formation des journalistes, and, later, the sailing school Les Glénans.
During World War II, he led a resistance movement named Défense de la France.
[1] The Canadian journalist Caitlin Kelly—who studied with Viannay at the Centre in Paris on an eighth-month journalism fellowship—later described him as "the most inspiring man I've ever met.
"[2] During the first year of the German occupation, Viannay married the former Hélène Mordkovitch.
[1] The French Fondation de la Résistance awards an annual prize for resistance-era histories, the Prix Philippe Viannay-Défense de la France.