Conan O'Brien and Denis Leary Discover They Are Third Cousins

The comedians learned of their shared Irish heritage through family research and a late-night TV connection.

Denis Leary and Conan O'Brien, both of Irish descent, have confirmed they are third cousins, sharing roots in Killarney, Ireland.
Leary's uncle Patrick identified the connection after watching him appear on 'Late Night with Conan O'Brien' and connecting family history details.
The link was traced through Conan's mother, Ruth Reardon O'Brien, whose family lived in Worcester, Massachusetts, where Leary's relatives also settled.
Both comedians noted their physical similarities and shared career beginnings as writers for 'Saturday Night Live.'
O'Brien, who recently lost both parents within days of each other, is preparing to host the upcoming 97th Academy Awards.