The 30-year-old begins filming with the teen serial next month as Brendan, a sinister new arrival with a dark past.
Scanlan has appeared in a variety of small TV and film parts since 2004, but Hollyoaks will be his first major acting job. His previous credits include appearances on Irish medical drama The Clinic and the 2008 movie Freakdog.
Speaking of his Hollyoaks appointment, Scanlan told the Evening Herald: "I've just booked a leading role in it which starts in May and I'm a bad-ass in it. I play a bad guy with a dark secret who goes by [the] name of Brendan.
"It's a good healthy stint of six to seven months and I can't wait to get started. It's all about new experiences and Hollyoaks has a very impressive history. It's great to be part of it."
Brendan is likely to feature in a storyline with established character Cheryl Brady (Bronagh Waugh) as it was recently revealed that a "very nasty man indeed" would arrive in the village to make the Irish favourite's life a misery.
Scanlan is the latest in a string of new signings which have been announced since new producer Paul Marquess joined the Chester-based drama in January.
Since taking the helm at the soap's home in Liverpool, Marquess has instigated a mass shake-up of the soap's cast and creative teams.
Last week, he announced a hoard of new names, including former Bill actress Kim Tiddy, who he hopes will help reinvent the serial.
Yesterday, Digital Spy exclusively revealed that Channel 4 chiefs have recommissioned a third run of E4 spin-off Later.