The count, uncle of King Carl Gustaf of Sweden, was the youngest son of Gustaf VI Adolf of Sweden and Crown Princess Margareta, born Princess Margaret of Connaught and a granddaughter of Queen Victoria.
Bernadotte was born Prince Carl Johan of Sweden in 1916 but lost his title in 1946 when he married journalist Kerstin Wijkmark - Sweden's monarchy at the time did not allow princes to marry commoners and keep their titles.
Following Wijkmark's death in 1987 he remarried Countess Gunnila Märta Lousie Wachtmeister af Johannishus.
He claimed not to regret losing his royal status. In a 1983 interview he admitted that he went through a difficult time when he gave it up, but said he maintained a good relationship with his father, who was then crown prince. He was granted the title Count of Wisborg by Grand Duchess Charlotte of Luxembourg.
Bernadotte and Kerstin lived in London for much of their life together and he worked as a businessman. They had two adopted children. He moved back to Sweden following his wife's death and settled in Halland, in the south-west of the country.
In a statement released by the Royal Court, King Carl XVI Gustaf and Queen Silvia described Bernadotte as a "dearly beloved family member who meant a lot to the whole family thanks to his friendliness and humour. We will remember Carl Johan as a respected and lovable relative whom we always valued deeply, not least due to his knowledge of our family's history, which he always shared so generously.
The palace said Bernadotte died peacefully at Ängelhom hospital at 9pm on Saturday.
He is survived by his second wife and his two children, Monica and Christian. Royal spokesman Bertil Ternert said funeral arrangements would be handled by his immediate family.