Stoolball is a sport that dates back to at least the 15th century, originating in Sussex, southern England. It is considered a "traditional striking and fielding sport" and may be an ancestor of cricket (a game it resembles in some respects), baseball, softball, and rounders. The sport has been called "cricket in the air". There is evidence to suggest that it was played as a tradition by milkmaids who used their milking stools as a "wicket" and the bittle, or milk bowl as a bat, hence its archaic name of bittle-battle.

The sport of stoolball is strongly associated with Sussex and has been referred to as Sussex's 'national' sport and a Sussex game or pastime. The National Stoolball Association was formed in 1979 to promote and expand stoolball. The game was officially recognised as a sport by the Sports Council in early 2008. The National Stoolball Association changed its name to Stoolball England in 2010 on the advice of the Sports Council and was recognised as the national governing body for stoolball in England in 2011. The organisation is recognised by Sport England.

The game's popularity has faded since the 1960s, but it continues to be played at a local league level in Sussex, Kent, Surrey and the Midlands. Some variants are played in some schools. Teams can be ladies only or mixed. There are ladies' leagues in Sussex, Surrey and Kent and mixed leagues in Sussex.

Stoolball is attested by name as early as 1450. Nearly all medieval references describe it as a game played during Easter celebrations, typically as a courtship pastime rather than a competitive game. The game's associations with romance remained strong into the modern period. Written by William Shakespeare and the Sussex-born playwright John Fletcher, the comedy, The Two Noble Kinsmen used the phrase "playing stool ball" as a euphemism for sexual behaviour.

Stoolball makes an appearance in the dictionary of Samuel Johnson, where it is defined as a game played by driving a ball from stool to stool.

Stoolball seems to have been one of the earliest sports in which women participated. Activities for women before about 1870 were recreational rather than sport-specific in nature. They were typically non-competitive, informal, rule-less; they emphasised physical activity rather than competition. In contrast, stoolball allowed women to participate in competitive sport.

A "fine match of stoolball" is recorded as having been played in June 1747 by a total of 28 women at Warbleton. The first inter-county stoolball match took place between the women of Sussex and Kent in 1797 at Tunbridge Wells Common on the historic border between the two counties. Sussex women wore blue ribbons to represent the county while the women of Kent wore pink ribbons.

Sussex historian Andrew Lusted has argued that between 1866 and 1887 the Glynde Butterflies stoolball team were the first women in England to be considered sports stars. In 1866 the first recorded stoolball match took place between teams of named women representing villages as the Glynde Butterflies took on the Firle Blues. Other teams included the Chailey Grasshoppers, Selmeston Harvest Bugs, Waldron Bees, Eastbourne Seagulls, Danny Daisies and Westmeston.