Conan O'Brien Family History

Conan Christopher O’Brien was born on April 18th, 1963 to Thomas and Ruth O’Brien in Brookline, Massachusetts.

He was one of six children.  Coming from such a large Irish Catholic family, he has said that some of his early memories were about trying to make his Dad or his brothers laugh at the dinner table.  He began doing his Charlie Chaplin impersonations when he was in third grade.

He was also a hard-working student who went to Harvard University.  He graduated magna cum laude in 1985.  Yer his heart was not really into his studies.  He said instead: “Comedy was something that I stumbled into.”  He began writing for the college humor magazine Harvard Lampoon and later became its editor.

Comedy and Talk Shows.  Following Harvard Conan relocated to Los Angeles and landed a sketch comedy writing gig for the then-fledgling Fox Network.  After jumping around on a number of unsuccessful shows, Conan moved to New York and won an Emmy for his writing on  NBC’s Saturday Night Live.

In 1993 he first came in front of the cameras when he wound up as host of NBC’s talk show Late Night with Conan O’Brien.

As a host he found the show an ideal vehicle for him to strut his goofiness and wacky self-deprecating humor.  Despite some initial unfavorable reviews and even threats of cancellation, Conan’s show developed over time and became highly regarded.  He went on to host Late Night for a total of sixteen years.

However, it did not work out when he replaced David Letterman in 2010 on the late night Tonight Show (another Irish American Jimmy Fallon was to succeed there).  Instead he went on to host a new show Conan on the cable TV station TBS.  This kept him in the public eye until his eventual retirement from regular broadcasting in 2021.

He is still around.  Conan hosted the Academy Awards in March 2025.

Conan’s Goofiness

When Burt Ward was asked to give a speech at Harvard about his role on Batman back in 1966, he brought along the original Robin costume, said to have been valued at half a million dollars.

Some students dressed as security guards came up to him and told him that they would keep the costume safe.

Then, in the middle of Ward’s speech, one student stood up and asked: “When is a costume not a costume?  When it’s stolen.” The lights dimmed and the students grabbed the costume and made off.  After snapping pictures of one another wearing the cape, they later called Ward and gave the costume back.

The ringleader of the gang?  Harvard Lampoon editor Conan O’Brien.

Ireland and Massachusetts

Conan has said that his ancestors came from Ireland from both sides of his family.  And they subsequently married only other Irish Catholics.  Thus his lineage in America is 100% Irish Catholic.

This entirely homogenous ancestry was confirmed by a DNA test in 2019.  He remarked that being entirely descended from just one ethnic group is extremely rare for an American.

As for his parents Conan said:  “Both of my parents are very Irish Catholic. My mother’s side came from the Cork area.  My father’s family came from Dungarvan in Waterford. They came to central Massachusetts to take up farming.  Irish married Irish.”

Ireland.  The starting point on Conan’s father side was a farming townland near the village of Gallbally in SE Limerick.  This part of Limerick is close by north Cork and south Tipperary.

The O’Brien name goes back a long time in Gallbally.  An abbey for Franciscan friars was founded there in 1204 by Donagh Cairbre O’Brien.  In the early/mid 1800’s Gallbally was the home of Conan’s ancestors Daniel O’Brien and his wife Margaret from Emly in Tipperary.

On a visit back to Ireland in 2024 Conan was able to find out exactly where the family home had stood near Gallbally.  For Conan the whole place seemed picturesque with its views over to the Galtee Mountains.  But for his ancestors it must have been a dismal life that drove them to emigrate.

Conan’s maternal ancestors also came from the west of Ireland.  Theirs was the small village of Kilcummin near Killarney in county Kerry.

John Riordan and his wife Margaret Daly lived there in the mid-1800’s.  There were nine Riordan households recorded in the 1852 Kilcummin census; and both the Riordan and Daly names appear in the old Kilcummin graveyard.  Conan visited the place in 2024.

Massachusetts.  Both sides – Thomas O’Brien on Conan’s father side and Patrick Riordan or Reardon on his mother side – came to Worcester county in central Massachusetts in the 1870’s.  Both married Irish girls there and both farmed.  Patrick in Worcester died young in 1898 at the age of thirty-two; Thomas in Millbury lived until 1924.

Succeeding generations showed remarkable upward mobility over the years:

• son Francis O’Brien, born in 1896, was a banker in Millbury; and son James Reardon, born in the same year, a police officer in Worcester.
• while grandchildren Thomas O’Brien and Ruth Reardon who married in 1958 excelled in medicine and the law.

Conan’s Parents

Conan’s parents Thomas and Ruth O’Brien were married for sixty-six years.

His father was an epidemiologist at Peter Bent Brigham Hospital, its first Director of Infectious diseases and its Head of microbiology.  He also worked as a Professor at Harvard Medical School.  Thomas finally retired from his work in 2019 at the age of ninety.  He died five years later in December 2024, just three days before his wife Ruth passed away.

His mother Ruth studied at Yale Law School and was one of only four women in her law school class there.  She made history as the second woman partner at the Boston law firm of Ropes & Gray. She also reportedly retired in her nineties, not long before her death.

So Conan came from a serious high-minded Irish Massachusetts family.  But his home life could be chaotic.  Conan has said: “There were six kids, two dogs, a cat, my grandmother, a parakeet – I’m not kidding.  That house was kind of madness sometimes.  Lovely madness, but madness still the same.”

Conan has credited his father for getting him into comedy at a young age, showing him Charlie Chaplin and Marx Brothers movies. “The loudest I’ve ever heard anybody laugh was sitting next to him in a theater watching Peter Sellers in a Pink Panther movie,” Conan has said.

Conan O’Brien’s Family Tree

• Limerick
• Daniel O’Brien (died in 1879) m. Margaret Dempsey in Tipperary in 1818
• – Jeremiah O’Brien (1825-1906)

• Jeremiah O’Brien m. Ellen Noonan (1835-1904) in Gallbally, Limerick in 1855
• – Daniel O’Brien (b. 1855)
• – Thomas O’Brien (1861-1924)
• – Nora O’Brien (1870-1919) m. John McNamara
• – Ellen O’Brien (b. 1874) m. Gilman Merritt

• Parents and Son
• Dr. Thomas Francis O’Brien m. Ruth Reardon in Worcester in 1958
• – Neal O’Brien (b. 1959)
• – Luke O’Brien (b. 1961), m. Ilsa Martin, lawyer
• – Conan O’Brien (b. 1963)
• – Kate O’Brien (b. 1965), actress
• – Jane O’Brien (b. 1967), moved to California, screenwriter
• – Justin O’Brien (b. 1973), m. Joanna Shea, lawyer