Notable for his role as Gregory Goyle in the popular Harry Potter movies, Herdman is also known for his portrayal of Ben on the BBC One series UGetMe.
The first Harry Potter film, Harry Potter and the Sorcerer's Stone, was released when Herdman was in his early teens.
He was cast in a small role in the 2012 thriller Piggy.
The son of Jessica Herdman and actor and professional rugby player Martin Herdman, he grew up with three older brothers. With his girlfriend Jessica, Herdman had a son named Morgan.
He and Jamie Waylett both rose to fame for their roles in the Harry Potter films.