The Gavin and Stacey finale was watched by a total of 20.9 million viewers, according to the latest ratings.
But BARB has revealed the much-awaited final episode of the sitcom was not the most-watched Christmas Day TV show.
Viewing for the last 28 days - which includes catch-up or on-demand viewing - reveals Wallace and Gromit’s latest adventure, Vengenace Most Fowl, reached 21.6 million viewers.
The BBC said both shows had set Christmas Day records for television not seen in over 20 years.
Charlotte Moore, BBC’s Chief Content Officer says: "These figures exceed all expectations, to reach over 20 million is an astonishing milestone in 2025."
"These two quintessentially British shows couldn’t be more different but what unites them is their undeniable quality and the fact they are best in class."
"I am in awe of the creative genius that is Aardman, Nick Park, Merlin Crossingham, Ruth Jones and James Corden and I’m very proud of the long standing relationship we have with them. It’s been a privilege to support their exceptional creative talents over decades.”
The record breaking numbers for both specials make them the UK’s biggest scripted and animation shows since modern records began in 2002.
Co-creators Ruth Jones and James Corden added: "What a testament to the BBC to have achieved such impressive viewing figures on Christmas Day. We are so proud to have been a part of it.”