The item, which was declared ‘unfit for a Princess’ was one of a number of lots to be auctioned.
The estimated price it was expected to sell for was between £15,000 and £20,000.
But it sold for more than twice the amount at £44,000 at Burstow & Hewett Auctioneers in Battle.
Included with the bike was a newspaper article from 1981 and a framed letter from Gerald Stonehill, who originally bought the item from Diana.
A spokesman said: “The auction world has seen a huge rise in interest for Royal memorabilia in recent years, and with Princess Diana’s bicycle having previously sold for £9,200 in 2018, this is a star lot to watch go under the hammer.
“Lady Diana enjoyed riding the blue Raleigh Traveller Bicycle around Kensington, London. She’d leave it chained to the railings outside her London flat, even commenting in interviews about having a wheel stolen once before.
“However, shortly after her engagement to Prince Charles in 1981 the bike made newspaper headlines as she was ordered to stop riding by Royal officials.
“Branded the ‘shame bike’, this item is a famous symbol of Diana’s oppression. Something she loved being taken away; and control over her public appearance for the reputation of what is deemed acceptable for a lady of the British Royal Family.”
Mark Ellin, from Burstow & Hewett, said: “We’re absolutely thrilled with the price the bike made on Wednesday.
“It sold to a buyer in the US, although I’m not sure why they bought it. They were bidding against another US bidder who is an agent for sports stars.
“The price they paid including commission was £57,200. Absolutely incredible price for a bike that probably cost about £20 originally.
“The worldwide media interest has been amazing. We have been interviewed on Woman’s Hour on Radio 4, on BBC news, CBS news in America, and in numerous newspapers and magazines.
“It really shows how much interest there still is in anything associated with Diana.
“It’s been a lot of fun to deal with.”