On May 30, 2026, 1,848 people sharing the last names O’Sullivan and Sullivan assembled in Castletownbere, County Cork, to break the world record for the largest gathering of people with the same surname [1, 2, 3]. Guinness World Records officials verified the count at the event held on a local school football pitch [1, 3].
The previous record was set by the Gallagher clan in 2007, when 1,488 members met in County Donegal [1, 2, 3]. Jim O’Sullivan, one of the event coordinators from Castletownbere, greeted the turnout with pride, saying, "But people turned out in their numbers, and we did it. So we’re asking the Gallaghers, back on your shoulders now. Next time up, you’ll beat us!" [1]. Kelly Sullivan, the clan chieftain who hosted the gathering, said, "I feel blessed to have grown up as part of the wider Sullivan-O’Sullivan family. We make a team that can’t be beat." [1]
Many attendees traveled from abroad, including members of the Irish diaspora from Boston and a family from Mexico. Kevin Sullivan, 75, from Boston, called the event an "incredible feeling" to see so many fellow Sullivans and O’Sullivans together [1]. Michel Sanchez O’Sullivan, 35, whose family is the only known O’Sullivan family in Mexico, attended to connect with his Irish heritage. He said, "As far as we know, we’re the only O’Sullivans in Mexico. It’s great to be here to get to explore my Irish roots and meet the rest of the family!" [1]
The event faced a rainy start, causing doubts about the turnout, but attendance quickly grew and secured the new record [1, 2, 3]. Participants passed through turnstiles for an initial count before the official tally was done on the pitch [1, 3].
Kelly Sullivan, who was presented with the clan chieftain chain of office in Boston in 2023, helped host the event alongside Jim O’Sullivan [1, 3]. The gathering drew a wide circle of the large O’Sullivan and Sullivan families both locally and globally.
The record stands as the largest same-surname assembly verified by Guinness World Records. The clan now looks forward to future reunions that may once again challenge the Gallagher record.
