SS Dwinsk was a British-flagged ocean liner sunk by U-151 in World War I. The ship was previously the third Rotterdam for the Holland America Line, C.F. Tietgen for the Scandinavian America Line, and, as Dwinsk, for the Russian American Line. The ship was put under Cunard Line management in 1917, and sailed under the British flag until sunk on 18 June 1918.