The National League North club today announced that the 87-year-old has passed away.
He had been watching Nuneaton since he was ten years old.
The club are to hold a tribute to him before Saturday’s home game with Guiseley.
Club Secretary Adam Etheridge said: “He was a proper gentleman from a different generation and never had a bad word to say about anyone.
“Rex was a ray of sunshine through the difficult times and always lifted our spirits.
“Home or away, everyone knew Rex and was keen to extend every courtesy to him as he had always done for them.
“Rex is a great loss and impossible to replace.”
Manager Jimmy Ginnelly added: “Rex was a fantastic man it was always nice to see him when you entered through the sliding doors.
“He always greeted you with that beaming, warm smile. He was a legend for the Boro’, a fantastic Ambassador, and will be sorely missed by everyone at the club.
“My fondest memory of Rex was him turning me away because I was wearing jeans.
“Saturday will be a difficult day but we’ll be hoping to honour Rex with three points. I’m sending my sincere condolences to Rex’s family at this very sad time.”