Which ship was the first purpose-built ocean liner of the 21st century?

Queen Mary 2 was the first purpose-built ocean liner of the 21st century.

Built for Cunard by Chantiers de l’Atlantique in Saint-Nazaire, France, Queen Mary 2 was designed specifically for regular North Atlantic crossings. She entered service in 2004 and succeeded QE2 as Cunard’s principal transatlantic liner.

Unlike most modern cruise ships, Queen Mary 2 has a hull and propulsion arrangement intended for sustained operation in the open Atlantic. Her design includes strengthened structure, higher speed and enclosed passenger spaces suited to ocean weather.

Queen Mary 2 is often called a cruise ship because she also operates cruises, but her principal distinction is her ocean-liner role. She should not be confused with the original RMS Queen Mary, which entered service in 1936 and is now permanently preserved in Long Beach.