The 26-year-old, who previously played the role of Dan in disability-themed mockumentary Cast Offs, is to play a yet-to-be-announced character in the teen show after being recruited by producer Paul Marquess.
Mitchell has used a wheelchair since 2002, when he lost the ability to walk following a car crash. He landed his new TV part last week during a meeting with the Hollyoaks production team at the show's base in Liverpool.
Speaking of his casting, Mitchell told the Derry Journal: "I thought getting a part in Cast Offs was fantastic and then came a part in Doctors - but this is really big. This is a long term acting job - they don't come much bigger than this and I'm really excited about it.
"I went over last Thursday morning and met with the producer on the village set for the show. As soon as I walked through the door, he started to talk about my character and I soon discovered that the decision had already been taken to put me in the show."
He continued: "I'll need to move to Liverpool, I reckon that'll probably be at the end of October. I don't actually start filming until November and my character, which is being worked on at the minute, will not appear on the screen until late January or early February."
Mitchell is the latest in a long line of new signings which have been announced since Marquess took office at the teen soap in January.