He is best known for a handful of Disney Channel original movies and for portraying Jake Pierce in The Ring Two, Kevin Fischer in Final Destination 3, and Ian Thomas in Pretty Little Liars.

At a young age, he began acting in commercials, print work, vocal performances, and local theater (Stage Struck Studios) in Oklahoma.

Merriman's other roles include the horror films Halloween: Resurrection (2002), The Ring Two (2005), and Final Destination 3 (2006).

He played Henry Dunn in the original pilot presentation for Harper's Island, but was replaced by Christopher Gorham when the series was picked up by CBS.

In 2011, he appeared as linebacker Jon Abbate in The 5th Quarter, a film about the 2006 football season of Wake Forest University.