You probably know him as the guy who wanted to turn a theater into a robotics lab. Or maybe you recognize him as one of the insufferable "finance bros" getting served a very stressful dinner. Mark St. Cyr has this specific energy—a mix of sharp-edged pragmatism and unexpected warmth—that makes him a standout even when he’s surrounded by A-list stars.
He isn't just a face you see on Disney+.
His career spans everything from gritty procedural dramas to high-concept horror satires. Originally from Lafayette, Louisiana, St. Cyr has quietly built a filmography that reflects a massive range. He’s a BFA grad from Elon University and an ABC Diversity Showcase alum. That training shows. Whether he’s playing a historical figure or a cynical teacher, there’s a groundedness to his work that feels remarkably real.
The Breakthrough: Benjamin Mazzara and the Disney+ Era
If we're talking about mark st cyr movies and tv shows, we have to start with High School Musical: The Musical: The Series (HSMTMTS). For four seasons, he played Benjamin Mazzara.
Mazzara was the foil. He was the "logic" to Miss Jenn’s "emotion." Most actors would play the STEM teacher as a one-note villain who hates the arts, but St. Cyr didn't do that. He gave the character a dry, deadpan humor that made him a fan favorite. You eventually realize he isn't anti-art; he’s pro-future.
The chemistry between him and Kate Reinders (Miss Jenn) provided a sophisticated subplot for the adults watching the show with their kids. Seeing him return in the final season felt like a necessary homecoming for the series. It anchored the show's evolution.
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From Finance Bros to Harlem Renaissance: Notable Film Roles
It’s easy to get pigeonholed in Hollywood. St. Cyr has successfully dodged that.
Take the 2022 film The Menu. He played Dave, one of the three tech/finance guys (alongside Rob Yang and Arturo Castro). It was a masterclass in playing "entitled." He managed to be genuinely annoying in a way that served the story’s tension, yet he held his own in scenes featuring Ralph Fiennes and Anya Taylor-Joy. That’s not an easy feat.
Diversity in Film Credits
He’s been in more than just blockbusters, though. His filmography is a mix of indie darlings and prestige biopics:
- Marshall (2017): He played a sophisticated lover of Langston Hughes. It was a brief but pivotal role that showcased his ability to handle period pieces and heavy emotional subtext opposite Jussie Smollett and Chadwick Boseman.
- Modern Persuasion (2020): Here, he pivoted to romantic comedy, playing Brian, a "nerdy-hipster" art curator. It was a complete 180 from the stiff intensity of his earlier roles.
- Root Letter (2022): A gritty adaptation of a Japanese visual novel where he played Adam.
- Snare (2026): One of his most recent projects involves a role in this thriller, which began principal photography in Los Angeles in early 2026.
The Procedural King: Guest Spots You Might Have Missed
Before he was a series regular, St. Cyr was the guy popping up in every major New York-based production. If you’ve watched a marathon of Law & Order or Chicago P.D., you’ve definitely seen him.
Honestly, his guest spots are a "who's who" of modern television. He was in Person of Interest as an airport cop. He played Arthur Burton in Chicago P.D. (Season 5). He even showed up in Sneaky Pete and Kevin Can Wait.
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What’s interesting is how he handles these "one-and-done" roles. In Law & Order: Special Victims Unit, he played Jamal Turner, a young professional. Even with limited screen time, he brings a level of specificity that makes the character feel like a person with a life outside the script.
Recent Work and What's Coming in 2026
St. Cyr is currently at a point where he’s moving from "that guy from that show" to a recognizable lead.
In 2025, he guest-starred in Elsbeth as Ronan Gaines. It was a perfect fit for his style—quirky, slightly heightened, but still believable.
He’s also a filmmaker in his own right. He’s written, directed, and produced several shorts like Below The Belt and Everything Is Fine. This "multi-hyphenate" approach is becoming the standard for actors who want longevity in the 2020s. He isn't just waiting for the phone to ring; he’s creating the work.
Where to Watch Mark St. Cyr
If you want to catch up on his best work, here is where most of it lives:
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- Disney+: High School Musical: The Musical: The Series (All seasons).
- Max/HBO: The Menu.
- Amazon Prime: Sneaky Pete and several of his indie features.
- Peacock: His various Law & Order and Chicago P.D. episodes.
Why He Matters for the Future of TV
Mark St. Cyr represents a specific type of modern actor. He’s versatile enough to do a Disney musical, a cynical horror-comedy, and a gritty police drama without ever feeling out of place.
He brings a "Lafayette-to-NYC" work ethic that is pretty obvious if you follow his career trajectory. He isn't chasing fame as much as he’s chasing interesting, complex characters. Whether it's a yoga teacher in Accommodations or a real estate developer in Chicago P.D., he finds the logic in the character.
If you're looking to follow his journey, keep an eye on his upcoming thriller Snare. It marks a move toward more intense, central roles that should finally push him into the household-name territory he’s been hovering near for years.
Next Steps for Fans:
If you enjoyed his performance in The Menu, go back and watch his arc in Season 1 of HSMTMTS. The contrast is wild. You can also check out his personal website to see some of the short films he has directed, which give you a much better sense of his personal creative voice beyond the characters he plays for the big studios.