The comedy flick is a remake of the 2011 French-Canadian hit The Delivery Man.
Delaney (45) recognises this as one of his best chances to make a name for himself in Hollywood.
"Listen, if you play football then ultimately you want to play in the FA cup final and if you do TV and comedy -- that's really the ultimate place to do it," he says.
Delaney's new movie centres on a middle-aged man, played by Jennifer Aniston's ex Vince Vaughn, who finds out that he fathered 533 children via sperm donation.
Dubliner Delaney plays the part of Vaughn's brother and says working with the Wedding Crashers star was a pleasure.
"Vince Vaughn is a gentleman," Delaney says. "A funny guy and very charming. He's also a big man, 6ft 6ins -- very tall. Jaysus, he's practically a giant."
The comedy is set in the New York borough of Brooklyn.
Versatile Delaney says he had no trouble with the accent as he's a big fan of US drama The Sopranos.
"I did have to put on the accent, but watching The Sopranos helped. I'd say the American actors will be raging when they hear the part went to an Irish guy."
The film also features What Richard Did star Jack Reynor.
It is Delaney's first major US feature role but the Zonad star has been steadily carving out a career in the States over the past three years. He's appeared in Julianna Margulies' series The Good Wife and Kiefer Sutherland's Touch.
But Simon, who is the new patron of the Variety Children's Charity at the Odeon in Dublin, said the downside is spending so much time in America away from his family.
"It is very hard being away from home," he said. "Because my kids are so young. They are babies and they miss their dad. Skype is a wonderful invention but the novelty wears off after about two weeks. They don't understand why they can see you and talk to you but can't sit on your lap, so they get bored."
Luckily, Simon is back in Dublin for the next six months, filming the fourth and fifth seasons of award winning cartoon Roy for RTE2.
"My wife is delighted; it's lovely being back for such a long stretch of time. It's the only time in my career where I've known what I'm doing for six solid months."
In February Delaney will be back on our TV screens in a much darker role. The Dublin native will star in Gillian Anderson's BBC2 drama The Fall, about a Belfast serial killer.