A graduate of the National Theatre School of Canada in 2005, Guillaume has performed on most Montreal stages and has toured across Quebec and internationally. Co-founder of Terre des Hommes with Marc Beaupré and François Blouin, he has never ceased to be involved in bold and innovative creation projects, such as Caligula Remix and Dom Juan Uncensored. His interest for new forms of writing and technology led him to complete a program in direction and production/interactive medias at the INIS in 2016, where he was awarded the Louise-Spickler Excellence Scholarship. 

Since then, he specialises mainly in direction and sound scriptwriting: Fréquences (2019), an audio series considered for a Numix prize 2020 for the best Fiction or Experimental podcast. Son de cloche (2020), a humerous podcast hosted by Catherine Éthier, who discusses issues in the world of education. As well as L’académie de voyage Bruno Blanchet (2021), the favorite sound destination for surprising, touching and hilarious travel stories. 

Nonetheless, Guillaume has not neglected hi career as an actor. On TV, we can see him in Ruptures, District 31, Bad Blood 2, Mémoires vives, Béliveau, Indéfendable, C'est comme ça que je t'aime and in Le Bohneur. On the web, notably in Terreur 404 and L’Ascenseur. On the big screen, he played in Vivre à 100 milles à l’heure by Louis Bélanger,  Les Nôtres by Jeanne Leblanc, and in Luc Picard's feature films Gallant : confessions d’un tueur à gage and Les rois mongols.