Rhod Maclennan, from Morpeth, died at home with his wife, Sue, and granddaughter, Jade Crawford, by his side.
The 68-year-old had been diagnosed with cancer in June.
Sue said: “As heartbroken as I am, the messages of love and support have been amazing. It’s been quite over-whelming.
"We’ve been getting messages from all over the world with people saying he was the best Santa they had ever seen.
"Only Rhod could have chosen Christmas Day to depart, and he's made sure he'll never be forgotten.
"The exit he made was straight out of a Walt Disney film.
"Christmas is Rhod's day now: people will be dressing up as Santa and eating good food, and thinking of him.
"He was very much of the view that life is for living, and he wouldn't want Jade and I to be upset. Of course we are missing him terribly, but there's not a single thing you can think of about Rhod that doesn't make you smile, that doesn't have joy in it.
“He was a wonderful man and incredibly uplifting to be around.”
He was well known for running 'Northern Doodles', a local labradoodle group, and could regularly be seen at Blyth beach walking his own four dogs.
In 2011, he even won a competition on the BBC’s The One Show to find the owner that most looked like its pet!
He was also a keen actor and played an extra in the likes of Vera, Beowulf and Inspector George Gently.
Until recently, Rhod had been Bamburgh Castle’s Santa, speaking to children via Zoom from his grotto due to Covid-19 restrictions.
For several years he was also Father Christmas at Whitehouse Farm, near Morpeth, and also did private house calls for autistic children.
Karen Larkin, events manager at Bamburgh Castle, said: “It is absolutely heartbreaking. Rhod was an incredible person and I am just so thankful that I got to know him, his wife Sue and his grand-daughter Jade so well over the past year or so.
"The fact he cared so much and truly believed in everyone was incredibly heart-warming. For me though, his most endearing quality was that he truly believed in himself.
"Quite simply, he was Father Christmas and because he believed it, just spread warmth and happiness to everyone he met.
"I am unsure if anyone will be able to put into words just how much he will be missed but one thing I know for sure is that he will never ever be forgotten.
"He was an absolute legend and I am sure those who met him will smile with every memory they have of him.
"We had parents booking their children for a session with Santa because they'd seen Rhod before and thought he was the real Father Christmas.
"Bamburgh Castle launched its first Father Christmas experience in August and by October, it had virtually sold out, and I believe that was down to Rhod's reputation.”