The dinner – including oysters, beef, spring lamb, and mallard duck – was served on the evening of April 11 1912 after the liner left Queenstown in Ireland for New York during its fateful maiden voyage.
The menu went under the hammer at Henry Aldridge & Son in Devizes on Saturday 11 November and sold for £84,000. It was estimated to go for between £50,000 - £60,000.
More than 1,500 passengers and crew died when the Titanic struck an iceberg on the evening of 14 April and sank the following day.
The 6.25ins x 4.25ins menu bears an embossed red White Star Line burgee and would have originally shown gilt lettering depicting the initials OSNC (Ocean Steamship Navigation Company) alongside the lettering RMS Titanic.
Auctioneer Andrew Aldridge said: “The latter shows signs of water immersion having been partially erased, the reverse of the menu also clearly displays further evidence of this.
“This would point to the menu having been subjected to the icy North Atlantic waters on the morning of April 15 either having left the ship with a survivor who was exposed to those cold sea waters or recovered on the person of one of those lost.
“Having spoken to the leading collectors of Titanic memorabilia globally and consulted with numerous museums with Titanic collections, we can find no other surviving examples of a first-class April 11 dinner menu.
“The menu is a remarkable survivor from the most famous ocean liner of all time.”
Among the first-class passengers onboard the Titanic were multi-millionaire John Jacob Astor, millionaire Benjamin Guggenheim, Sir Cosmo and Lady Duff Gordon and socialite Molly Brown.
The menu was discovered in a photo album from the 1960s after the passing of the late Len Stephenson by his daughter and son-in-law.
Mr Stephenson was a keen historian of his hometown Dominion in Nova Scotia and collected and preserved many records.
Other items which featured in the sale included a Swiss-made pocket watch owned by and recovered from second-class Titanic passenger Sinai Kantor which sold for £97,000.
A first-class tartan-patterned deck blanket, which was likely used during the rescue of passengers, fetched £96,000.