Genest turned to acting and in his early years played a son on the immensely popular French-language radio show, La famille Plouffe and on its follow-up television series.

The first was Nikki, Wild Dog of the North followed by 1962's Big Red and the following year he was cast in the lead of The Incredible Journey.

Moving to Hollywood, Émile Genest went on to play character roles in a variety of films including The Cincinnati Kid (1965), The King's Pirate (1967), In Enemy Country (1968), The Hell with Heroes (1968), and Don't Just Stand There!

In the early 1960s, Genest turned to performing on television, appearing in a large number of guest roles in a variety of series such as Mission: Impossible, Route 66, Gunsmoke, Combat!, The Rat Patrol, Perry Mason, The Virginian, Ironside and others.

His elder son is Green Party of Canada unelected politician Claude Genest.