Rheon, who plays Simon Bellamy, exits the show alongside Antonia Thomas (Alisha), who confirmed her departure earlier this week (December 19).
Rheon commented on his exit: "Thanks for all the comments and support. I'm so grateful for the opportunity that Misfits gave me and all the fun I had doing it. But I have left now and look forward to doing exciting new things. The show must go on! X"
Robert Sheehan departed the sci-fi show at the end of the second series, but ratings have remained strong following the addition of Joseph Gilgun to the central cast.
Misfits concluded on Sunday night with 860k viewers watching on E4. A fourth series has already been confirmed by the broadcaster.
> 'Misfits' third season finale: recap
Watch Digital Spy's recent interview with Iwan Rheon below: