The transparent black number, which Kate wore during a charity fashion show at Saint Andrews University in Scotland in 2002, went under the hammer at a packed sales room in central London on Thursday.
The price of $125,000 or 89,000 euros, which included a buyer's premium of £13,000, far exceeded the initial estimate of £10,000 by Kerry Taylor Auctions.
A man at the back of the sales room who refused to give his name said he bought it on behalf of an individual he would identify only as "Nick from Jersey".
While speculation swirls about the dress Kate will wear for the royal wedding in Westminster Abbey on April 29, the most famous garment she has worn so far has spent years squashed in a wardrobe full of junk.
Middleton, then aged 20, strode down the catwalk wearing the knitted mesh slip-dress and black underwear during the student show nine years ago when she and William were students at the university.
William, second in line to the throne, had paid £200 for a front-row seat and soon afterwards their friendship blossomed into romance. Some reports suggest he first tried to kiss her at a party later that evening.
The strapless dress was designed by Charlotte Todd, who was a fashion and textile design student in 2000 at the University of the West of England when she produced it for a project entitled "The Art of Seduction".
The dress cost £30 to put together and was intended as a skirt.
Two years later, Todd was invited to submit a garment for the annual Saint Andrews fashion show. The piece was selected for Middleton, who wore it as a dress.
"I am totally speechless, and feel very emotional," said 31-year-old Todd after the sale. "I really didn't think it would make that amount."
"I am planning to put some of the money towards a deposit for a house, but perhaps I may use some to change my career," she added.
Kerry Taylor, the auctioneer, said: "The sale did fantastically well and went above expectations throughout. I am delighted that the dress made a 'princely sum'."
Thursday's sale also included two gowns worn by William's late mother, Diana, princess of Wales.
| Posted: at | |
maffrodisiac
proly
wiselove
Lizzie4Shizzie
messi2011
deboalabi262
Slimme
femilux
MissyBarbie
Josh4love
Cedron5jesus
nuhu1
kahyordey
giftmurphy
TRENDING GISTS 
Osun Community Boils As Gunmen Kill Farmer In Communal Dispute
Pastor Tobi Adegboyega Loses Deportation Battle After His Church Was Shutdown Over £1.87m Fraud
FCT Police to Start Impounding of Vehicles With Tinted Glasses
Ogun Student Teacher Attempts Suic!de After She Accidentally Caused Damaged to Pupil's Eye
Nigeria Starboy, Victor Osimhen Reportedly Acquires Private Jet
Manchester City v Nottingham: English Premier League Match,Team News,Goal Scorers and Stats
Fire Razes INEC Office In Delta, Destroy Election Materials