Three mainland-based property developers paid 1.63 million Hong Kong dollars for the "Queen Tartufo" Alba truffle at a charity auction on Sunday, a spokeswoman for the exclusive Ritz-Carlton hotel said.
The price for the 750-gram (26-ounce) truffle works out to 2,173 dollars-a-gram.
The delicacy, from Alba in Italy's Piedmont region which is famed for its autumn truffles, has been shipped to Hong Kong.
It will be served in a private dinner at the hotel's restaurant on Sunday, the hotel said.
The price beat the record held by Hong Kong billionaire Sir Gordon Wu, who last year paid 125,000 euros (160,787 dollars) for a 1.5 kilogram white truffle at the annual Worldwide Alba Truffle Auction.
The money raised by the sale will be donated to Mother's Choice, the Hong Kong-based charity that provides care for women facing pregnancy crises.
It is the third year in a row that a buyer from Hong Kong snapped up the truffle in the annual sale.
The past truffle season has been one of the worst in recent years in Alba, reports say, forcing up prices for top class truffles to 8,000 euros (11,700 dollars) a kilogram.