The radio star will make a one-off appearance in this evening's episode and by all accounts goes down a storm with residents on the street.
The DJ will play himself and shows up to preside over the official opening of the town's new community centre.
According to a spokesperson for the soap: "Larry will come in amidst much excitement to open the centre.
"Everyone was delighted to have him come along and he did a great job," he told the Herald.
Viewers will see Larry drafted in by Seamus McAleer at the last minute when Orla tries and fails to get a celebrity to host the opening.
Meanwhile, popular Fair City star Tracey McGuigan will find herself at the centre of an explosive storyline tonight when her attempt to persuade hubbie Dominic to take Viagra goes very wrong.
The pair, who are not long married, have hit a rough patch in recent times and the Herald can reveal things are about to get much worse in weeks to come.
According to Hilda Fay who plays the much loved character: "Dominic's under a lot of pressure with the construction trade going down the tubes and he can't cope.
"He's lost an awful lot of jobs in the last few weeks and the stress is really starting to show.
"Tracey just wants a bit of love and affection, that's her main concern, but she's not getting any joy from him so she's understandably devastated and eventually turns to the option of Viagra which doesn't go down very well," she told the Herald.
Tonight's episode will see the pair have a terrible argument and exchange some sharp words.
"Dominic's a pressure cooker waiting to go off," Hilda revealed. "There's going to be a lot of drama in the next few weeks.
"He tried to hit his daughter Kylie earlier in the week and she moved out.
"He does have a history of abuse which is kind of worrying so it will be interesting to see how it all pans out," she added.
Ironically, Hilda is hoping things escalate for her character Tracey in the coming weeks.
"Of course when you're an actor you always want drama and no matter what comes at you, you do your best to portray it on screen.
"If things get ugly for Tracey, I'll throw myself into it.
"You don't really have to do too much research for these stories generally because there's an excellent team of script writers behind you but we'll have to see how it plays out.
"It should make for some good viewing," she added.