Wallace Hartley has become part of the ship's legend after leading his fellow musicians in playing as the doomed vessel went down, most famously the hymn Nearer My God To Thee.
Hartley and his seven fellow band members all died in the tragedy in April 1912 after the liner sailed from her home port of Southampton, 1,500 people died after the ship hit an iceberg.
His violin, which had been a gift from his fiancee Maria Robinson, was apparently found in a case strapped to his body when it was recovered from the icy Atlantic waters.
Its re-emergence in 2006, when it was reportedly discovered in an attic in Yorkshire, prompted heated debate over its authenticity.
Titanic specialist auctioneers Henry Aldridge and Son insist nearly seven subsequent years of research and tests have proved it to be the genuine article.
Now the violin - accompanied by a leather luggage case initialed W. H. H. - is being put up for sale along with a host of items from the ship at the public auction in Devizes, Wiltshire.
Andrew Aldridge, a valuer with the auctioneer, said it was likely to break the world record fee for a single piece of memorabilia from the Titanic.
The violin has a reserve price of between £200,000 and £300,000 but is expected to fetch as much as £400,000, he said.
More top news
Dry but breezy tonight, cloud and some bright spells on Sunday.
Dry but breezy this evening and overnight with cloud and sunny spells tomorrow.
Mostly dry with sunny spells and a fresh south-westerly breeze.