Mark McKenna is set to star in Peacock’s ONE OF US IS LYING, from UCP, a division of Universal Studio Group.

Based on Karen M. McManus’s New York Times best-selling novel, ONE OF US IS LYING is the story of what happens when five high schoolers walk into detention and only four make it out alive. Everyone is a suspect, and everyone has something to hide.

McKenna will star as Simon, a brainy outcast and the creator of a gossip app that holds the entire school captive. His posts are juicy, snarky, cruel, and most importantly: always true. He takes pride in exposing his classmates as the “liars and hypocrites they really are.” Even though all of his classmates read his app, they also all hate him for it.

McKenna is known for his titular role in the Amazon series WAYNE and his breakout role in John Carney’s SING STREET.

He is represented by Authentic Talent and Literary Management, Independent Talent Group, UTA and Michael Mahan at Peikoff Mahan.

Previously announced cast: Marianly Tejada (Bronwyn), Cooper van Grootel (Nate), Annalisa Cochrane (Addy), Chibuikem Uche (Cooper), Jessica McLeod (Janae), Barrett Carnahan (Jake) and Melissa Collazo (Maeve).

ONE OF US IS LYING will be coming soon to Peacock.

ONE OF US IS LYING is produced by UCP, a division of Universal Studio Group. Darío Madrona (co-creator of “Elite”) will serve as showrunner and executive producer. Erica Saleh (“Evil”) wrote the pilot and will executive produce. The series is also executive produced by John Sacchi and Matt Groesch of 5 More Minutes Productions who developed the pilot. Filmmaker and actress Jennifer Morrison directed and produced the pilot.