From his breakout television days, when he brought quick-witted humor and tragic emotional depth to a hit supernatural drama, to anchoring major blockbuster franchises, viral short films, and acclaimed indies, O’Brien has established himself as one of his generation’s most versatile performers.
1. Stiles Stilinski – Teen Wolf (2011–2017)
The role that started it all. As Scott McCall’s sarcastic, fiercely loyal best friend, O’Brien transformed what could have been a standard sidekick into the undisputed heart of the series. His chilling performance during Season 3’s “Void Stiles” possession arc showcased a dramatic range that instantly caught Hollywood’s attention.
2. Thomas – The Maze Runner Trilogy (2014–2018)
Taking the helm of a massive dystopian YA franchise, O’Brien starred as Thomas, a young man fighting to navigate lethal labyrinths and post-apocalyptic trials. His grounded vulnerability, physical commitment, and leadership chemistry anchored all three films to over $940 million in global box-office success.
3. Joel Dawson – Love and Monsters (2020)
In this post-apocalyptic creature feature, O’Brien played Joel, a lovelorn survivor embarking on a dangerous 85-mile journey to reconnect with his high school girlfriend. Partnered with a fan-favorite dog named Boy, O’Brien brought charm, physical comedy, and genuine emotional resonance to the Oscar-nominated sleeper hit.
4. “Him” – Taylor Swift’s All Too Well: The Short Film (2021)
Opposite Sadie Sink, O’Brien delivered a captivating, intense performance in Taylor Swift’s 10-minute cinematic short film. Portraying a charismatic yet dismissive partner, O’Brien captured the complexities of an asymmetric relationship, driving the project to instant pop-culture phenomenon status.
5. Colin – Not Okay (2022)
Exposing his razor-sharp comedic instincts, O’Brien took on a hilarious supporting turn as Colin, a bleached-blonde, vape-obsessed clout chaser. Leaning fully into the absurdity of the character, O’Brien stole every scene in the satire on influencer culture.
6. Dan Aykroyd – Saturday Night (2024)
Stepping into the shoes of a comedy icon, O’Brien portrayed original Saturday Night Live cast member Dan Aykroyd in Jason Reitman’s chaotic ensemble biopic. Capturing Aykroyd’s kinetic energy and distinctive cadence during the frantic 90 minutes leading up to SNL’s very first 1975 broadcast, O’Brien earned high praise from critics.
7. Paris Lang – Caddo Lake (2024)
In the M. Night Shyamalan–produced atmospheric mystery thriller, O’Brien delivered a grounded, emotional performance as Paris, a man unraveling family secrets tied to a missing girl and an elusive lake anomaly. The performance earned him a Gotham TV Award nomination, cementing his continuing evolution into complex dramatic storytelling.