Glen is best known for his work on TV's "Game of Thrones" and "Downton Abbey."
On the Oct. 26 installment of "Haven," he will portray a "refined yet bitter man who has been trapped inside his house for more than 27 years," a synopsis said.
Based on Stephen King's novella "The Colorado Kid," "Haven" follows former FBI agent Audrey Parker, who becomes a police officer in the small town of Haven, Maine, and soon discovers its many secrets. The show stars Emily Rose, Lucas Bryant and Eric Balfour.
Season 3 of the show is to begin Sept. 21.