An average of 610,000 people tuned in to watch The Late Late Show’s London special on Friday night.
The programme, the first to be broadcast from London in 36 years, was the most watched Late Late Show so far in 2018.
It had a 52% share of viewers watching television on Friday night, while the audience peaked at 695,000 viewers.
1.15 million people tuned in for a minute or more of the broadcast over the course of the night.
The programme also proved popular on RTÉ Player and was streamed almost 50,000 times over the weekend.
Host Ryan Tubridy said: “Bringing The Late Late Show to London was a huge undertaking but we felt it was important that, in these times of Brexit, we should acknowledge and celebrate the ties between these two islands.
"I am delighted that people responded in such huge numbers”.
The show, which came live from Central Hall, Westminster, featured interviews with Graham Norton, Brendan O’Carroll, Angela Scanlon, Imelda May, Finbar Furey, Laura Whitmore, Mick McCarthy, Barry McGuigan and a Brexit debate with Nigel Farage, Alastair Campbell, Baroness Dee Doocey and Liam Halligan.
Spoken Word artist Stephen James Smith delivered a performance of This Community, while a Trad supergroup featuring members of The Corrs, Clannad, The Chieftains, The Dubliners and John Spillane also performed.
The show also featured interviews with members of the Irish community in Britain across a range of areas.
The ratings were compiled by TAM Ireland Ltd/Nielsen TAM.