The area is bordered to the west by the River Ingrebourne which forms the boundary with Hornchurch, to the north by the A127 Southend Arterial Road, to the east by the M25 motorway and North Ockendon and to the south by the borough's boundary with Thurrock.
Upminster is famous locally for Upminster Windmill, a smock mill currently being restored to become the only working windmill in Greater London. Locally, the windmill is an icon for the town and is used in the names of some local businesses and the badges of local sports teams. Upminster is more widely known for being the eastern terminus of the District Line and the location of a London Underground depot at Cranham. An intact 16th century barn is currently used as a museum of nostalgia; it is known locally, although falsely, as a "Tithe Barn". Upminster is the location of three Havering parks and open spaces, the main Upminster Park, Hall Lane Park (known locally as 'the Rec') and Clockhouse Gardens.
Upminster is home to Roomes Stores, a large independent family-run department store, originally located in Upton Park, which occupies several buildings on the principal street, Station Road. Upminster is also the home of the Travel Club of Upminster, one of Britain's oldest tour operators founded in 1936 by Harry Chandler. The high street has a good selection of restaurants but has little in the way of nightlife. Upminster is also famous for Ian Dury, the rock singer who named his 1981 album Lord Upminster after the area.
The placename Upminster is first recorded in 1062 as Upmynstre. It means higher minster and is formed from Old English upp and mynster. The up refers to the higher ground around St Laurence church, in relation to the River Ingrebourne.
There were two principal manors, and one smaller landholder, at the time of Domesday in 1086, both known as Upminster; although in different spellings. Clearly these manors were well-developed, going concerns for long before the Norman Conquest. The field boundary pattern in the south of the parish suggests at least a middle Saxon origin. One of the manors had been donated to Waltham Abbey during the reign of Edward the Confessor. William Derham (resident in Upminster 1689-1716), the first man to measure the speed of sound, did so from the tower of St. Laurence's Church. Dr. Derham's papers on the speed of sound (in the Proceedings of the Royal Society) describe how he used paired pocket watches, a telescope up the tower of St. Laurence's, and friends around the area (in places such as Rainham) who could be trusted to fire a gun at a precise moment. In 1709, he observed with a telescope a cannon firing on Blackheath. The doors in the south side of the spire used for this purpose are still extant.
Upminster formed an ancient parish in the Chafford hundred of Essex. Like much of contemporary Havering, it formed part of Romford Rural District from 1894 to 1934. In 1934 the rural district was abolished and the parish was added to Hornchurch Urban District. When the urban district and parish were abolished in 1965 by the London Government Act 1963, Upminster was transferred to Greater London to became part of the London Borough of Havering, although it retains use of the county of Essex in all its postal addresses. In 1851 the parish covered an area of and had a population of 1,228. In 1951 the population was 13,038.
London Buses has several services to Romford, Hornchurch, Cranham and Upminster Bridge.Upminster Bridge tube station is half way between Upminster and nearby Hornchurch. Bell Corner in Upminster forms the eastern end of the A124 road which passes through East London as far as Canning Town. Upminster is served by London Bus routes 248, 346, 347, and 370. To the south of Upminster is Damyns Hall Aerodrome.