Royal Caribbean International is a Norwegian/American cruise line brand based in Miami, Florida and owned by Royal Caribbean Cruises Ltd.. With 42 ships in service under 5 different brands and one more under construction, it controls a 24.8% share of the world cruise market.

All ships since 1991 have names ending in "of the Seas." It is the world's second-largest cruise line operator, after Carnival Corporation & PLC. As of March 2009, Royal Caribbean Cruises Ltd. fully owns five cruise lines: Royal Caribbean International, Celebrity Cruises, Pullmantur Cruises, Azamara Club Cruises and CDF Croisières de France, plus has a 50% stake in TUI Cruises. Previously Royal Caribbean Cruises also owned 50% of Island Cruises, but this was sold to TUI Travel PLC in October 2008. Royal Caribbean Cruises Ltd. was formed in 1997 when Royal Caribbean Cruise Line, founded in 1968, and Celebrity Cruises, founded in 1988, was then purchased. The decision was made to keep the two cruise line brands separate following the merger; as a result Royal Caribbean Cruise Line was rebranded Royal Caribbean International and Royal Caribbean Cruises Ltd. was established as the new parent company of both Royal Caribbean International and Celebrity Cruises. A third brand under Royal Caribbean Cruises ownership was formed in 2000 when Island Cruises was created as a joint venture with British First Choice Holidays. Island Cruises became an informal cruise line on the British and Brazilian markets. In November 2006, Royal Caribbean Cruises purchased Pullmantur Cruises based in Madrid, Spain. Onwards from that point the company expanded radically with the creation of new cruise lines: Azamara Club Cruises was created in May 2007 as a subsdiary of Celebrity Cruises and CDF Croisières de France, aimed at French-language customers, in May 2008. Another new cruise line, TUI Cruises began operations in 2009. The brand is aimed at a German-speaking audience and is a joint venture with TUI Travel PLC. TUI AG had previously become the owner of 50% of Island Cruises following their acquisition of First Choice Holidays in 2007. In October 2008 Royal Caribbean Cruises sold their share of Island Cruises to TUI.