Eton fives, a derivative of the British game of fives, is a handball game, similar to Rugby fives, played as doubles in a three-sided court. The object is to force the other team to fail to hit the ball 'up' off the front wall, using any variety of wall or ledge combinations as long as the ball is played 'up' before it bounces twice. Eton fives is an uncommon sport, with only a few courts, most of them as part of the facilities of the independent schools in the United Kingdom.

Eton fives is a sport developed in the late 19th century at Eton College. The shape of the court used now is taken from the chapel at Eton College, where A. C. Ainger and some of his friends developed a simple set of rules in 1877. The rules have been modified since that time to those seen now, but the essential components are still the same.

Much earlier than the formalisation of Eton fives, a court was built in the grounds of Lord Weymouth's Grammar School, now Warminster School, in 1787, the School's 80th year. It is claimed that Thomas Arnold took the game with him to Rugby School leading to Rugby Fives. The court at Warminster School survives but is rarely used.

City of Norwich School (formerly Eaton (City of Norwich) School) is possibly unique in being a state-run comprehensive school which houses two fives courts. Matches have been undertaken on the courts between Eaton & Eton, but in the 1990s the courts were used as car parks for teaching staff. Since 2013 one of the courts has been used for fives, whilst the other is now a boiler room.

Dale Vargas, a retired teacher at Harrow School, where he was master in charge of Fives, has written and published a book about history of Eton fives, titled "Eton Fives: A History". The co-author is Peter Knowles.

An Eton fives court consists of three walls, with the left-hand wall interrupted by a buttress approximately halfway up the court. There are also two levels to the court, the front being around six inches higher than the back half of the playing area. On the front wall is a vertical black line about three-quarters of a metre from the right wall; this is used during the serve and return process detailed later. There is a diagonal ledge that circumvents the entire 'top-step' at about chest height; it is this ledge which the ball has to hit or go above to be 'up'. Below this ledge, at knee height, is a horizontal ledge about two inches wide, and which is only present on the 'top-step'. This is merely here because of the origins of Eton fives as the ledge is present at the chapel in Eton College.

The diagonal ledge drops vertically at the edge of the 'top-step' and then returns to normal at a slightly lower height on the bottom step, running to the back of the court. At the back are brick columns that jut out slightly into the court, which vary in width from school to school, these "buttresses" are usually anywhere from 2 – 10 inches in width. Shots very rarely hit this part of the court, but once they do it is usually very effective for winning a point. Between the buttress and the top step is a small rectangular area about 10 cm sq, often referred to as the 'pepper pot'. If the ball is hit into the pepper pot it is almost always point-winning. Each of the courts at varying schools differ in some way, leaving room to modify how school's courts are built to a certain extent. In this way the 'home team' will often have an advantage over a visiting side because of their knowledge of the court's characteristics and layout.

Fives has many rules that are similar to other court type games, such as tennis or squash: