Next Big Thing: Rachel Marsh’s Rise from ‘Adults’ to ‘The Love Hypothesis’

When you hear the name Rachel Marsh these days, most people will first think of that ridiculously catchy fake‑K‑pop number that blew up on social media from the FX series Adults. The scene, complete with over‑the‑top hand‑jabs and a chorus that somehow sticks in your head for days, turned a supporting gig into an internet meme.

But Marsh isn’t just a one‑track wonder. Fresh off that viral moment, she’s leaping into the world of romantic comedies, playing the bright‑eyed grad student Anh in Prime Video’s upcoming adaptation of Ali Hazelwood’s bestselling novel The Love Hypothesis. In a relaxed Zoom chat with The Hollywood Reporter, the actress opened up about the new role, the friendship at the heart of the story, and why she loves getting to be funny on screen.

“I love anytime women are funny,” Marsh says, chuckling. “It feels like a little rebellion, especially when the jokes land in a way that feels true to us.” She adds that the part of Anh wasn’t something she actively chased; director Claire Scanlon and writers Sarah Rothschild and Hazelwood wanted to avoid the tired ‘quirky best‑friend’ trope and instead give Marsh a character who’s genuinely important to the plot.

That importance shines through in the chemistry with co‑star Lili Reinhart, who plays Olive. “She is important in this story. She also is funny,” Marsh explains. The two actresses spent a summer filming in Montreal, and according to Marsh, their off‑screen camaraderie made the on‑screen friendship feel effortless. “Lili is so sweet, such a great scene partner. Building that trust was pretty easy,” she notes, smiling at the memory of endless coffee breaks and late‑night script reads.

The transition from a viral K‑pop parody to a heartfelt rom‑com may seem like a leap, but for Marsh it’s more of a natural evolution. In Adults, she played Carly, the girlfriend of Samir (Malik Elassal), and it was the fake song “Hiccups (Body Go Crazy)” that stole the spotlight. “When I read the script I thought, ‘You guys know this is too good,’” she recalls, describing the moment co‑creator Ben Kronengold asked if she’d be comfortable portraying a K‑pop star.

“I had tears in my eyes, full‑body chills,” Marsh admits, laughing. The scene was directed by former SNL video director Paul Briganti, who encouraged her to go all‑in with the most ridiculous hand gestures and facial expressions. “It sparked something in me—what if I could sing, but I’ve never had the right training?” she muses, hinting that perhaps a hidden pop career could be on the horizon.

Fans have been clamoring for the full version of “Hiccups” to hit streaming platforms, and Marsh is right there with them. “I really think they should put the song on Spotify or something. People just need a moment of joy,” she says, her excitement palpable.

Back to The Love Hypothesis, Marsh says the first fan screening was a “buzzing” experience. The audience reacted positively, and while she’s trying not to spoil anything, she can’t hide her anticipation for the official release on the 23rd of this month. “It’s fun, this waiting period. Seeing the first batch of reactions makes me even more excited for when everyone gets to watch,” she confides.

She also admits she hadn’t actually read Hazelwood’s novel before being cast. “I’d seen the cover everywhere—airports, bookstores. It was a bestseller, so it was on my radar. I never got to read it before the job, which I think was a blessing. It let me discover the story fresh, without preconceptions,” she reflects, grateful for the chance to bring the book’s spirit to the screen.

Whether she’s delivering punchy jokes alongside Lili Reinhart or performing a tongue‑in‑cheek K‑pop routine, Marsh seems to thrive on moments that let her be both vulnerable and wildly entertaining. As she puts it, “Every girl has that little voice wondering, ‘What if I can sing?’ And maybe that’s where the best stories start.”