The property was put up for auction against the wishes of Bokassa's son, Radio France Internationale reported. Georges Bokassa appealed to President Nicolas Sarkozy to stop the court-ordered sale, saying the chateau belongs to the family.
A lawyer representing the buyer said he paid 915,000 euros ($1.2 million) and plans to use Chateau Hardricourt on the Seine as a family home.
The elder Bokassa, born in what was then French Equatorial Africa in 1921, served in the French army and then transferred to the army of the CAR after independence. He seized power in a coup in 1965 and was ousted by the French in 1979 after hundreds of school children were arrested for protesting uniform requirements and about 100 killed.
He was rumored to have engaged in cannibalism while he was head of state.
Bokassa lived at Hardricourt for a few years in the 1980s. He returned to the CAR, was sentenced to death, spent several years in prison and then died in the country in 1996.