Isleworth (/ˈaɪzəlwəθ/ EYE-zəl-wərth) is a suburban town in the London Borough of Hounslow, West London, England.
It lies immediately east of Hounslow and west of the River Thames and its tributary the River Crane. Isleworth's original area of settlement, alongside the Thames, is known as Old Isleworth. The northwest corner of the town, bordering on Osterley to the north and Lampton to the west, is known as Spring Grove.