Born in 1983 in the Ardennes, Guillaume Massart alternately directs, produces or edits creative documentaries.

In 2010, he became one of the three founders of the production company TRIPTYQUE FILMS.

After 11 short films, his first feature, In The Open, was released in French cinemas in February 2019.

His second feature, Detention, co-produced by TRIPTYQUE FILMS with TS Productions, will have its world premiere at the 2026 Cannes Film Festival, in the ACID programme.