Jack Thayer, American businessman (d. 1945)
John Borland Thayer III (December 24, 1894 – September 20, 1945) was a first-class passenger on RMS Titanic who survived after the ship struck an iceberg and sank on April 15, 1912. Aged 17 at the time, he was one of only a handful of passengers to survive jumping into the frigid sea. He later wrote and privately published his recollection of the sinking.