The 60-year-old comedian, Conan O'Brien, filmed his cameo during a visit to Ireland in early January while recording an episode for his HBO Max travel series, Conan O'Brien Must Go. O'Brien, who has often spoken about his Irish roots, visited his home of Galbally, Co Limerick, before heading to the set of Ros na Rún in An Spidéal, Connemara.

"Getting to work with the cast and crew of Ros Na Rún was a delightful highlight of my trip to Ireland, and I apologise in advance for inadvertently butchering my mother tongue," said O'Brien.

During his cameo, O'Brien portrays a feisty delivery man who clashes with the village rogue and publican, Tadhg Ó Direáin, played by Macdara Ó Fátharta. A "war of words" ensues between the two characters in Tigh Thaidhg. Marion Ní Loingsigh, series producer of Ros na Rún, said, "It was thrilling to get the request from Conan O’Brien... It was fun to create and film, and audiences will see a perfect delivery of Gaeilge by HBO’s Conan O’Brien in what is an abrupt but entertaining exchange with Tadhg.”

Ros na Rún, which is currently in its 28th season, is known for its celebrity guest appearances. Ros na Rún has previously featured stars like Stephen Fry, Daniel O'Donnell, and Nathan Carter. The episode is scheduled to air on Tuesday, April 30, at 8:30 pm on TG4.

Before O'Brien's appearance on Ros na Rún, the show will be featured on Conan O'Brien Must Go, airing on HBO Max this Thursday, April 18.