Hounslow is a large suburban district of West London, England, west-southwest of Charing Cross. It is the administrative centre of the London Borough of Hounslow, and is identified in the London Plan as one of the 12 metropolitan centres in Greater London.

It is bounded by Isleworth to the east, Twickenham to its south, Feltham to its west and Southall to its north.

Hounslow includes the districts of Hounslow West, Heston, Cranford and Heathrow. Although most of the district lay within the London Borough of Hounslow, some parts fall within the London Borough of Richmond upon Thames and the London Borough of Hillingdon including Heathrow Airport.

Most of Hounslow, including its Town Centre, the area south of the railway station and the localities of Lampton and Spring Grove, falls under the TW3 postcode. The TW4 postcode is made up of Hounslow West and parts of Cranford, whilst the TW5 postcode includes Heston and Cranford. Heathrow Airport and parts of Hatton comprise the TW6 postcode.