An area of the London Borough of Hillingdon.
South Ruislip tube station is served by the Central line of the London Underground. Although no bus route directly serves the station, London Buses route E7 serves one end of nearby Station Approach and route 114 serves the other.
The Royal Air Force station, RAF Northolt, is situated in South Ruislip near the A40 and the tube station. Most early RAF airfields were named after the nearest railway station; in this case Northolt Junction, the original name of South Ruislip station.
More information on the Wikipedia page