Rebel began her career on Sydney stages in the early 2000s, writing and producing her own work before becoming a leading voice in Australian comedy. She gained international fame as Fat Amy in the Pitch Perfect trilogy and starred in hits like Bridesmaids, Academy Award-winning Jojo Rabbit, Isn’t It Romantic, and Netflix’s Senior Year.

In 2024, her memoir Rebel Rising became a New York Times, Sunday Times, and Australian bestseller, ranking among the top celebrity memoirs on Audible and Spotify globally.

A patron of The Australian Theatre for Young People, Rebel made her directorial debut with The Deb, which premiered at the 2024 Toronto International Film Festival. She co-wrote, produced, and stars in the film, releasing worldwide in late 2025. Next, she stars in the action-comedy Bride Hard alongside Da’Vine Joy Randolph.