TUI Group is a German leisure, travel and tourism company; it is the largest such company in the world. TUI is an acronym for Touristik Union International. TUI AG was known as Preussag AG until 1997 when the company changed its activities from mining to tourism. It is headquartered in Hanover, Germany.

TUI Cruises is a cruise line based in Germany. It was formed in 2007 as a joint venture between the German tourism company TUI AG and the American cruise line operator Royal Caribbean Group, both of whom hold a 50% stake in the company.