Blair Athol is located about 6 km (4 mi) north of the Adelaide CBD, South Australia. Blair Athol borders the suburbs of Gepps Cross, Enfield, Prospect and Kilburn. The suburb is rectangular, stretching from Grand Junction Road in the north to Angwin Avenue in the south between Prospect Road on the west and Main North Road on the east. Blair Athol’s main and longest street is Florence Avenue.

Blair Athol is serviced by the G10 bus line between Adelaide and Grand Junction Road, travelling via Prospect Road and also bus routes 221, 222, 224, 225, 226, 228 and 229, G10, G10A, G10B which travel between Adelaide and various destinations in the Northern suburbs via Main North Road. Residents of Blair Athol can also catch the train line to and from the city. The station is located in Kilburn, several hundred metres from Prospect Road.