Denis Leary Hilariously Recalls How He Discovered He's Related To Conan O'Brien

Comedian and actor Denis Leary appeared on The Tonight Show Starring Jimmy Fallon and revealed that he is related to former late-night talk show host Conan O'Brien.

The Rescue Me star, currently starring in Netflix's dark comedy series No Good Deed, confirmed that he and O'Brien are third cousins.

Fallon presented Leary with a placard showing a photo of him juxtaposed with one of O'Brien, prompting Leary to joke that they both look like "two Irish aunts."

Leary explained how he and O'Brien are part of the same family tribe.

"My parents are Irish immigrants,” he told Fallon. “They come from the same town, Killarney in Ireland, and they came over [to the U.S.] in like 1950 by boat, but very few of their brothers and sisters came, so the bulk of the family was still in Killarney.”

“Well, my uncle Patrick, who was the oldest brother in the Leary family, we got him a satellite dish so that he could see the shows that I was on," he said.

Leary recalled the day his uncle happened to catch Leary on Late Night with Conan O'Brien, which the eponymous comedian hosted from 1993 to 2009.

“One night he’s watching me on Conan and he calls up one of my other cousins and says, ‘Listen, this guy that Denis is talking to, he’s one of our cousins.'”

Uncle Patrick's hunch turned out to be correct after he wrote down "what he thinks is going on."

Leary recalled the following conversation he had with his uncle.

“He said, ‘I think this guy is a Reardon.’ Reardon was the name of Conan’s mom."

“And he said, ‘I think there was a Reardon woman in Worcester, Massachusetts, who lived in a three-decker when your father and his brother Jerry got off in New York."

"...So they went up to Boston, to Worcester, because that’s where this Reardon woman lived and she put him in the basement and got him real jobs, like paying jobs under the table."

“So when I brought this paper to Conan and I said Reardon, he went, ‘Oh my God, my family was originally from Worcester and then went to Brookline.’ "

"So we’re like, ‘Oh my God, now look at us.’ "

People thought it was all quite grand.

Leary then turned to the audience and highlighted a physical attribute the family bloodline shares.

"First of all, we’re all legs, right?" he remarked, and got up on his feet to demonstrate how the waistline of his trousers was just an illusion to mask that his waist starts "right below my nipples."

He additionally pointed out:

"And look at my hair and look at Conan’s hair and look at our skin. It’s the same.”

Some fans highlighted a characteristic between the two that sets them apart.

Later on the program, Fallon joined Leary in singing an updated version of Leary's iconic song "A**hole," the lone single from his 1993 album No Cure for Cancer.

The new version demonstrated what makes an individual an a**hole more than 30 years after the song was released.

Newer examples of what a contemptible person would do included leaving a single-star rating on Amazon, starting a mosh pit at a Taylor Swift concert, COVID patients refusing to wear a mask, and singing the wrong lyrics to Wicked.

Both Leary and O'Brien started in comedy.

Leary was a stand-up comedian with appearances on MTV and his stand-up specials No Cure for Cancer and Lock 'n Load before taking on roles in comedic films, while O'Brien was a writer for SNL from 1988 to 1991 and the Fox animated sitcom The Simpsons from 1991 to 1993.

Last December, fans and industry rallied around O'Brien after his parents, Dr. Thomas O’Brien and Ruth Reardon O’Brien, passed away just three days apart after 66 years of marriage.