The event was held at Bonhams Auction House. Bonhams says the tooth, measuring more than 5 inches, is one of the biggest and best-preserved ever discovered.
The tooth, which was found in Montana earlier this year, sold to a private collector whose name was not released.
The T-Rex roamed western North America some 67 million years ago.
A fossil palm flower from Wyoming also sold at the auction for $50,000.
The Associated Press contributed to this report.