Goodman became a judge on the BBC show in 2004 and his final appearance was on the 2016 Christmas Day special.
He announced his retirement from TV six months ago and would have celebrated his 79th birthday on Tuesday.
A statement from his agent said: “It is with great sadness to announce that Len Goodman has passed away peacefully, aged 78.
“A much-loved husband, father and grandfather who will be sorely missed by family, friends and all who knew him.”
It is understood that Queen Camilla is a huge fan of the BBC dancing competition, and she and King Charles sit down together every Saturday night to enjoy the show when it is running.
Presenter of the BBC show, Tess Daly, previously revealed just how much of a fan of the show Camilla is during an interview with Hello! Magazine – and said Camilla has even been to visit the show’s set.
In October 2019, Tess said: “Camilla is a fan, she has been to visit us in the studio before and she spent half a day with us and it was wonderful.
“She was absolutely part of the whole process during the dress rehearsals, at the judge’s desk, handling the panels and she really enjoyed her day.
“She’s such a lovely lady and she actually invited all of our crew to Buckingham Palace two years ago and we filmed part of our routine there for Christmas.
“She’s told me they watch together so I hope they enjoy the series.”
