SS Imperator was an ocean liner built for the Hamburg America Line (Hamburg Amerikanische Paketfahrt Aktien Gesellschaft, or HAPAG), launched in 1912. Upon launch, she surpassed the just completed RMS Titanic by 24 ft., and she herself was surpassed the same year by SS Vaterland (later SS Leviathan) by 44 ft. She was the first of a trio of successively larger Hamburg America ships that included SS Vaterland and SS Bismarck built by the line for transatlantic passenger service.