Caid (Irish pronunciation: [kadʲ]) is the name given to various ancient and traditional Irish football games. "Caid" is now used by people in some parts of Ireland to refer to modern Gaelic football.

The word caid originally referred to the ball which was used. It was made out of animal skin, with a natural bladder inside.

Caid is believed to have influenced the modern sport of Gaelic football the rules of which were officially published in 1887 and is now organized and governed by the Gaelic Athletic Association (GAA) as an amateur sport.

There is some evidence that caid was taken around the world by the Irish diaspora, and some historians argue that it may have also played some part in the origins of Australian rules football, although such a relationship is controversial and the subject of debate.

The first recorded mention of football in Ireland was in 1308, when John McCrocan, a spectator at a football game at Newcastle, County Down was charged with accidentally stabbing a player named William Bernard. Football games are mentioned in the Statute of Galway, 1527, which allowed the playing of football and archery, but banned "'hokie' — the hurling of a little ball with sticks or staves", as well as other sports. The Sunday Observance Act of 1695 imposed a fine of one shilling for anyone found playing. Despite this, the earliest recorded football match in Ireland was one between Louth and Meath, at Slane, in 1712.

Caid may refer to:

CAID as an abbreviation may refer to:

Sport (or, in the United States, sports) is all forms of competitive physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Hundreds of sports exist, from those requiring only two participants, through to those with hundreds of simultaneous participants, either in teams or competing as individuals.

Sport is generally recognised as activities which are based in physical athleticism or physical dexterity, with the largest major competitions such as the Olympic Games admitting only sports meeting this definition, and other organisations such as the Council of Europe using definitions precluding activities without a physical element from classification as sports. However, a number of competitive, but non-physical, activities claim recognition as mind sports. The International Olympic Committee (through ARISF) recognises both chess and bridge as bona fide sports, and SportAccord, the international sports federation association, recognises five non-physical sports, although limits the amount of mind games which can be admitted as sports.