The 28-year-old actor has landed the role of DS Tom Anderson in the award-winning BBC drama, opposite Jamie Dornan and Gillian Anderson.
Colin's alter-ego, who is an officer involved in the hunt for serial killer Paul Spector (Jamie), will work closely with Detective Superintendent Stella Gibson (Gillian).
Colin said: "I'm delighted to be joining the cast of 'The Fall' for what is going to be an exciting and gripping second series. Allan Cubitt has written exceptional material and I feel very privileged to be working with him and the very talented cast."
Colin will join the cast, which is currently filming in Belfast, Northern Ireland, for the final three episodes of the second series of the gripping psychological thriller.
Meanwhile, the hunky star is set to pull in more viewers for the show after he won a National Television Award last year for his leading role in the the primetime series 'Merlin'.
'The Fall' is currently in the running for two BAFTA awards for series one after Jamie was nominated for the Leading Actor gong, and the show got a nod for Best Mini Series.
'The Fall' will return to screens with its second series at the end of the year.