[4] Arnaud started his career in his home country by landing a role in a comedy series called Taxi 0-22 and guest starring in several other Canadian shows.

[5] He also starred as Antonin Rimbaud in the French-Canadian film I Killed My Mother,[6] directed by Xavier Dolan.

Arnaud received a VFCC Award for Best Supporting Actor in a Canadian Film for the role,[7] and credits this with getting an agent in Hollywood which helped him audition for bigger parts.

The film was so physically and psychologically exhausting for Arnaud that he could not work for a month so took respite in a cabin in the woods.

[12] Arnaud featured in an episode of Emmy and Golden Globe Award winning show, Schitt's Creek as Sebastien Raine, David's ex-boyfriend and photographer.

[14] Also in 2019, Arnaud started shooting a psychological thriller called 'Home' about a young couple dealing with raising a newborn.

[12] Arnaud enjoys reading Sally Rooney novels such as Normal People and Conversations with Friends because they have the best ending sentences.