The specimen, known as Stan, is one of the largest, most complete and widely studied T-rex skeletons ever discovered.
It is named after the paleontologist Stan Sacrison who found the skeleton’s partially unearthed hip bones in 1987 in South Dakota.
The 67m-year-old dinosaur has previously been at the Black Hills Institute in South Dakota. It was estimated at $6-8m.
Christie’s said the price set a new world record for any dinosaur skeleton or fossil ever sold at auction.
It was sold at the Rockefeller Centre in New York during Christie’s Evening Sale of 20th Century Art on October 6.
Among the highlights of the sale were Mark Rothko's Untitled, 1967, which sold for $31.3m (including 14.5% buyer’s premium) and Pablo Picasso's Femme dans un fauteuil, 19 June 1942, which sold for $29.6m (including 14.5% buyer’s premium).