Rory Cowan is going from Mrs Brown's Boys to Carrigstown after signing up for Fair City.
The well-known Dublin actor is "over the moon" with excitement ahead of his debut on the popular RTE soap.
He will take on the role of Molly's brother John Bosco Walsh in scenes that will air this Sunday night.
The first episode will see his character arriving to the O'Briens' house and become immersed in a storyline regarding Rose's dementia.
It will be particularly poignant for the actor and comedy star, given that his own mother Esther suffered from dementia for years.
He revealed how he used to watch the long-running soap with her before she died in November 2018.
"I'm delighted to be eventually able to let people know I've joined the cast of Fair City," Rory said.
"The other cast members gave me a lovely welcome when I called in to see them. I feel right at home in Carrigstown.
"I'm delighted with the move there. Besides, if you're going to join a show, after you've been in a huge TV show already, then what's better than joining the biggest drama series on Irish television?"
Rory used to watch the show when it first aired 30 years ago this month but said he obviously dipped in and out of the storylines, given his time touring with Mrs Brown's Boys.
"For a good few years, when I was touring the world with Mrs Brown's Boys, I lost touch with what was happening in Carrigstown," he said.
"But when I left Mrs Brown's Boys to care for my mother, who had dementia, I got back into watching it again.
"Myself and my Ma used to watch the omnibus on Sunday afternoons. I've lovely memories of those Sundays with my Mam watching Fair City.
"If I'd been asked to go into another situation comedy, I probably would have said no, but being offered a role in Fair City was never going to be something I'd refuse," he added.
Rory left Mrs Brown's Boys in 2017 after 26 years with Brendan O'Carroll and his tight-knit clan.