The Blue Riband (pronunciation: /ˌbluː ˈrɪbənd/) is an unofficial accolade given to the passenger liner crossing the Atlantic Ocean westbound in regular service with the record highest speed. The term was borrowed from horse racing and was not widely used until after 1910. Under the unwritten rules, the record is based on average speed rather than passage time because ships follow different routes. Traditionally, a ship is considered a "record breaker" if it wins the eastbound speed record, but is not credited with the Blue Riband unless it wins the more difficult westbound record against the Gulf Stream.
Of the 35 Atlantic liners to hold the Blue Riband, 25 were British, followed by five German, three American, as well as one each from Italy and France. Thirteen were Cunarders (plus Queen Mary of Cunard White Star), 5 by White Star, with 4 owned by Norddeutscher Lloyd, 2 by Collins, 2 by Inman and 2 by Guion, and one each by British American, Great Western, Hamburg-America, the Italian Line, Compagnie Générale Transatlantique and finally the United States Lines. Many of these ships were built with substantial government subsidies and were designed with military considerations in mind.Winston Churchill estimated that the two Cunard Queens helped shorten the Second World War by a year. The last Atlantic liner to hold the Blue Riband, United States, was designed for her potential use as a troopship as well as her service as a commercial passenger liner.