Aghadowey (from Irish Achadh Dubhthaigh, meaning "Duffy's field") is a townland in east County Londonderry, Northern Ireland. It lies in Aghadowey civil parish, and is part of Coleraine Borough Council. It is close to the county boundary with County Antrim.
Aghadowey is also recognized as being the largest town-land in Europe.
Aghadowey is a popular angling area, with anglers fishing both the River Bann and the Agivey River.
Aghadowey Stadium hosts regular Motorcycle racing and Stock car racing also Rallying as an alltrak event, on the disused World War II airfield. Aghadowey was the home circuit (1.003 miles/1.614 km) of the Motor Cycle Road Racing Club of Ireland (MCRRCI) (now Bishopscourt Race Circuit near Downpatrick) and was first used for racing in 1975, after the club was forced to vacate their previous circuit at Maghaberry to make way for a new prison development.
Aghadowey also boasts a football team competing in the Coleraine and District league. They have notable rivalries with both Garvagh FC and Kilrea FC and have scored victories over the latter in recent years.
Aghadowey railway station opened on 19 February 1880, but closed on 28 August 1950.