RMS Republic was a steam-powered ocean liner built in 1903 by Harland and Wolff in Belfast, and lost at sea in a collision in 1909 while sailing for the White Star Line.

Known as the "Millionaires' Ship" because of the number of wealthy Americans who traveled by her, she was described as a "palatial liner" and was the flagship of White Star Line's Boston service.

In the early morning of 23 January 1909, while sailing from New York City to Gibraltar and Mediterranean ports with 742 passengers and crew and Captain Inman Sealby (1862–1942) in command, Republic entered a thick fog off the island of Nantucket, Massachusetts.

Severance, Professor John M. Coulter with wife and children, General Brayton Ives, St. Louis millionaire Samuel Cupples, historian Alice Morse Earle, and Mildred Montague, Countess Pasolini.

Taking standard precautions and maintaining her speed, the steamer regularly signaled her presence in the outbound shipping traffic lane by whistle.

Two passengers asleep in their cabins on Republic were killed when Florida's bow sliced into her, liquor wholesale manager Eugene Lynch's wife Mary and banker William J. Mooney.

On the busy North Atlantic route, assistance from at least one ship was believed to be ever-present and that lifeboats would be needed only to ferry all aboard to their rescue vessels and back until everyone was safely evacuated.

[9] By this time, the steamers New York and Lucania (from Cunard) had also arrived and waited while a futile attempt was made by Gresham to take Republic under tow.

Among these, The Washington Post reported, "Three million dollars in gold coins lie in the rotting hulk of the White Star liner Republic, lost off Nantucket in January, 1909.

"[15] The New York Times reported, "The White Star Liner Republic, lost off Nantucket Shoals in 1909, carried $3,000,000 in gold eagles.