Baldonnel (Irish: Baile Dhónaill, meaning "homestead of the O'Donnels"), is a townland, and industrial/agricultural area near Clondalkin, Tallaght, Lucan, Saggart and Naas, in west County Dublin. It is chiefly known as the location of the headquarters of the Irish Air Corps (Irish Air Defence Forces) at Casement Aerodrome, Baldonnel, which has been in operation for over 90 years in the locality, first as a RFC then a RAF aerodrome until the creation of the Irish Free State in 1922, when the Irish Air Corps (IAC) took command of the field.