Actor, author, director and teacher, we have seen Jonathan Gagnon in more than forty productions on the stages of Quebec and elsewhere: Le dieu du carnage and Lapin Lapin (Trident Theater), Les fourberies de Scapin, La Locandiera and La reine Margot (La Bordée et Denise-Pelletier Theater), Les mécaniques célestes (Théâtre des confettis – Quebec and Asian tour), Five Kings - L’histoire de notre chute (Théâtre des fonds de tiroirs, PàP Theater and Les Trois Tristes Tigres). 

In 2011, he received the Janine-Angers Award. In 2016, he was in Gloucester at the Theater La Bordée and in Ne m’oublie pas at Jean Duceppe Theater, under the direction of Frédéric Dubois. On the big screen, we have seen him in Claude Meunier's Le grand départ, in Alain Desrochers's Gerry and in Émile Gaudreault's De père en flic. On TV, he made a name for himself in Les Bougons, La Galère, René Lévesque, Rock et Rolland, Complexe G, Fugueuse, O', Sans rendez-vous, Les beaux malaises 2.0 and La faille 2. . 

In 2019, he performed at the Petit Champlain Theater in the play Boeing Boeing and at the Trident Theater in Le Cercle de craie caucasien.

Jonathan received the Paul-Hébert award in 2021, for his extraordinary performance in the leading role of Exercices de Style. 

During the 2022-2023-2024 seasons, he takes on the role of Luc Bernier in Maxime Giroux's movie Norbourg. He also plays in Cabaret, N'essuie jamais des larmes sans gants and Hosanna, from Michel Tremblay's text, which all played at the Théâtre du Trident.