Rys or RYS may refer to:
The Royal Yacht Squadron is one of the most prestigious yacht clubs in the world. Its clubhouse is Cowes Castle on the Isle of Wight in the United Kingdom. Member yachts are given the Suffix RYS to their names, and permitted to fly the White Ensign of the Royal Navy rather than the merchant Red Ensign flown by the majority of other UK registered vessels. The club's patron is Queen Elizabeth II and the club's admiral is Prince Philip who is also a former club commodore.
Founded on 1 June 1815 in the Thatched House Tavern in St James's, London as The Yacht Club by 42 gentlemen interested in sea yachting, the original members decided to meet in London and in Cowes twice a year, to discuss yachting over dinner. Membership was restricted to those who owned a vessel not under 10 tons. Today this is interpreted as a gentleman "actively interested in yachting".
The Earl of Yarborough, later first commodore of the club, welcomed the Prince Regent as a member in 1817. In 1820, when the Prince Regent became George IV, it was renamed the Royal Yacht Club.