The black Gibson ES-345 prototype was given to King by the guitar company for his 80th birthday. The headstock has “B.B. King 80” and a crown inlaid with mother-of-pearl.
It was one of several he called "Lucille."
The buyer wished to remain anonymous, a spokesperson for Julien's Auctions said. The auction house is selling more than 550 items from King's estate, including photographs, audio equipment, other guitars and clothing.
The sale of the guitar took place on Saturday in Beverly Hills, a few days after what would have been King's 94th birthday.
Julien's estimated its worth between $80,000 to $100,000, according to the auction house.
King called several of his guitars Lucille after an incident early in his career. He once ran into a burning nightclub to rescue his $30 guitar and later learned the blaze started when two men began arguing over a woman named Lucille and knocked over a kerosene stove.
He said he never found the woman but vowed to never endanger his life again.
Julien's said King's estate brought in around $1.3 million. An 18-karat gold ring he wore in photos sold for $16,250. It has "BB" encrusted with 22 diamonds.
The 15-time Grammy Award winner died in 2015 at 85. He is buried next to the B.B. King Museum and Delta Interpretive Center in Indianola, Miss., near the community where he grew up picking cotton in the Delta flatlands.
The Associated Press contributed to this report.