Stanmore is part of the London Borough of Harrow in Greater London. It is centred 11 miles (18 km) northwest of Charing Cross, lies on the outskirts of the London urban area and includes Stanmore Hill, one of the highest points of London, at 152 metres (499 ft) high. The district, which developed from the ancient Middlesex parishes of Great and Little Stanmore, lies immediately west of Roman Watling Street and forms the eastern part of the modern London Borough of Harrow.

The London Borough of Harrow is a London borough in northwest London, England; it forms part of Outer London. It borders four other London boroughs – Barnet to the east of ancient Watling Street, Brent to the southeast, Ealing to the south and Hillingdon to the west – plus the Hertfordshire districts of Three Rivers and Hertsmere to the north. The local authority is Harrow London Borough Council. The London borough was formed in 1965, based on boundaries that had been established in 1934. The borough is made up of three towns: Harrow, Pinner and Stanmore, but also includes western parts of Edgware.