Julie Lecoustre was born in 1987 in Avignon. She grew up near Cavaillon, in the Vaucluse, where her parents ran a hotel-restaurant. After working various jobs, she turned to filmmaking following her meeting with Emmanuel Marre in 2016. In 2018, as part of the Artists@work workshop at the Ateliers Varan, she directed the film délai d'asile.

In 2018, she joined Emmanuel Marre to write, conceptualize, and produce D'un château l'autre, which won the Pardino d'oro at Locarno. In 2020, they continued their collaboration by co-directing Rien à foutre, which was selected for the 2021 Critics' Week.