The Hamburg-Amerikanische Packetfahrt-Actien-Gesellschaft (HAPAG), known in English as the Hamburg America Line, was a transatlantic shipping enterprise established in Hamburg, in 1847. Among those involved in its development were prominent citizens such as Albert Ballin, Adolph Godeffroy, Ferdinand Laeisz, Carl Woermann, August Bolten, and others, and its main financial backers were Berenberg Bank and H. J. Merck & Co. It soon developed into the largest German, and at times the world's largest, shipping company, serving the market created by German immigration to the United States and later, immigration from Eastern Europe. On 1 September 1970, after 123 years of independent existence, HAPAG merged with the Bremen-based North German Lloyd to form Hapag-Lloyd AG.

An ocean liner is a type of passenger ship primarily used for transportation across seas or oceans. Ocean liners may also carry cargo or mail, and may sometimes be used for other purposes. Only one ocean liner remains in service today.