Haynes, who joined the cast for two-episodes in the sixth season, is happy to be back on the CW superhero drama.
The 'Arrow' executive producers said in a joint statement, "We're very fortunate and excited to welcome back Colton to 'Arrow'. While we've always enjoyed Colton's returns to the show, we couldn't be more thrilled to have him return as a proper series regular, and we're very excited about all the creative opportunities Roy Harper's return affords us."
The 29-year-old's credits also include 'Scream Queens' and 'American Horror Story'. (ANI)