GAA county colours and flags

The GAA county colours and flags of a GAA county are the colours of the kit worn by that county's representative team in the Gaelic Athletic Association's inter-county competitions, the most important of which are the All-Ireland Senior Football Championship and the All-Ireland Senior Hurling Championship and the Flags and banners of these colours are waved by supporters at these matches; in the build-up to a major match, flags and bunting are flown or hung from buildings, telegraph poles, and other fixtures across the county, especially in those regions where GAA support is strong.

Where a county's jersey is multi-coloured, these are the county colours. Where the jersey is a single colour, the colour of the shorts is also included. Shorts were formerly always white, but some counties adopted coloured shorts from the 1960s, such as Dublin's now familiar navy blue.

While each county council has a coat of arms, there are no official county flags. Flags with the GAA county colours serve as defacto county flags. However, there are no standardised formats for these, except Kildare whose flag, like their kit, is all-white. Typically, flags are formed as vertical bicolours or tricolours. The choice of which colour is nearest the hoist varies within a county. Moreover, horizontal stripes are used by some individuals. (This is common in County Offaly, where vertical county colours might be mistaken for the flag of Ireland; however other Offaly fans deliberately exploit this double significance.)

Flags with checkerboard, repeating stripes, and other patterns are also found. In recent years, flags have been commercially produced which feature the county's GAA logo on the flag. These logos are sometimes based on the official county coat-of-arms, but some have been replaced with unrelated designs. Fans may also wave other flags of the appropriate colours. For example, among the red-and-white flags used by individual Cork GAA supporters have been the flag of Canada and the ensign of the Imperial Japanese Navy. As Cork is nicknamed the "Rebel County", its fans have also flown the Rebel Flag of the American Civil War.

County Colours of Connacht

County Colours of Ulster

County colours of other counties

Some areas outside Ireland are treated as "counties" by the GAA, and their representative teams naturally have standard kit colours like the Irish counties.