The Royal National Lifeboat Institution (RNLI) is a charity that saves lives at sea around the coasts of Great Britain, Ireland, the Channel Islands and the Isle of Man, as well as on selected inland waterways.

The RNLI was founded on 4 March 1824 as the National Institution for the Preservation of Life from Shipwreck, with Royal Patronage from King George IV of Great Britain and Ireland. It was given the prefix 'Royal' and its current name in 1854 by Queen Victoria of Great Britain and Ireland. It has official charity status in both the United Kingdom and the Republic of Ireland.

The RNLI operates 444 lifeboats (332 are on station, 112 are in the relief fleet), from 235 lifeboat stations around the coasts of Great Britain, Ireland, the Isle of Man and the Channel Islands. The RNLI's lifeboats rescued an average of 22 people a day in 2009. RNLI lifeboats launched 9,223 times in 2009, rescuing 8,235 people. The RNLI's lifeboat crews and lifeguards have saved more than 139,000 lives since 1824. RNLI lifeguards placed on selected beaches around England and Wales, aided 15,957 people in 2009. The RNLI Operations department defines 'rescues' and 'lives saved' differently.