The civil parish has an area of 4.12 km² and in the 2001 census had a population of 8,756 in 3,970 households. For the purposes of local government, the parish falls within the district of Great Yarmouth.
Caister-on-Sea has been recently officially classified as a small town, but it also holds the title of being the most populated village in the UK. It was formerly served by Caister-on-Sea railway station, which is now closed.
The Scroby Sands wind farm, of 30, 2 megawatt wind turbines is located 2.5 km from the shore at Caister.
The name Caister-on-Sea derives from the Latin castra meaning castle, and Caister-on-Sea was the site of a Roman fort associated with the Saxon Shore. To the west of the naval base, a civilian settlement, a vicus, was established. Most of the original site now lies under modern housing. A small section, managed by English Heritage, is open to the public.lifeboat in the UK that is independent of the RNLI. A lifeboat at Caister was first documented in 1791, being used by the Caister Beach Company to salvage ships wrecked on the sand banks offshore from Caister. Between 1856 and 1969 lifeboats at Caister were operated by the RNLI. The current lifeboats, the Bernard Matthews II (a Dutch-built Valentijn 2000 offshore lifeboat) and the Jim Davidson OBE (a semi-rigid inflatable onshore lifeboat), are run by the Caister Volunteer Lifeboat Service, a registered charity supported entirely by public donation.
There is a large Haven holidays caravan and chalet park in the north end of the village adjacent to the coast. This is one of the oldest holiday camps in the British Isles which opened as the "Caister Socialist Holiday Camp" in 1906.
The Caister camp was the original home of the Caister Soul Weekender, with the first event held in 1979 playing host to the largest gathering of soul and jazz fans there had ever been. Caister Soul Weekender is still running twice-yearly events in nearby Great Yarmouth.