Yvon Deschamps was born on July 31, 1935, in Montreal's working-class Saint-Henri district.
He left school in 1951, after completing Grade 11, and in 1953, he found work in the record library at Radio-Canada's new television service.
At Radio-Canada, Deschamps discovered the performing arts, attending a boulevard theatre piece starring Georges Groulx and Denise Pelletier, which sparked his interest in theatre.
He enrolled in acting classes with François Rozet and Paul Buissonneau, and took the stage for the first time in 1957 at the Théâtre universitaire canadien, playing Pylade in a production of Jean Racine's Andromaque.
In 1959, Deschamps joined La Roulotte, Paul Buissonneau's travelling children's theatre, and the following year, he married Mireille Lachance, with whom he would later divorce in 1967.
In 1961, he became friends with Claude Léveillée, and they formed a company at Buissonneau's Théâtre de Quat'Sous in 1963.
Deschamps played his first film role in Jean-Claude Lord's Deliver Us from Evil (Délivrez-nous du mal) in 1965, although the film was not released theatrically until 1969.
That same year, he left his short career as a musician behind and opened Le Fournil, a restaurant in Old Montreal, followed by Saint-Amable in 1966, which unfortunately went bankrupt a few years later.
While the restaurants were open, Deschamps hosted his Boîte à Clémence, a boîte à chanson hosted by Clémence DesRochers, participating in the Le monde sont drôles (People are Funny) and Sois toi-même(Be Yourself) shows which opened there in 1967.
The latter show played a significant role in his career, as it was where the Yvon Deschamps "character" and his "good boss" role first appeared.
In the winter of 1968, finding himself broke and occasionally sleeping on friends' couches with his new girlfriend Judi Richards, Deschamps took a job at the Quat'Sous offered by his friend Buissonneau.
Deschamps proposed a musical review to Louise Forestier and Robert Charlebois with Mouffe on board, and very little rehearsal time, resulting in the revolutionary Quebec song show L'Osstidcho (L'hostie de show or "The freaking show").
Inspired by Arlo Guthrie's Alice's Restaurant, Deschamps made his first real monologue part of the review when Robert Charlebois did not want to learn his lines for the dialogue, instead deciding to strum the guitar.
In Les unions, qu'ossa donne? (Unions, What are they Good For?),Deschamps played a naïve worker extolling the great generosity and good-heartedness of his boss, making it clear that reality was not quite so rosy.
