Romford is a large town in east London, England, located 14 mi (23 km) northeast of Charing Cross. Part of the London Borough of Havering, the town is one of the major metropolitan centres of Greater London identified in the London Plan.

Historically part of the ancient parish of Hornchurch in the Becontree hundred of Essex, Romford has been a market town since 1247. It formed the administrative centre of the liberty of Havering until that liberty was dissolved in 1892, and became a civil parish of its own in 1849. Good road links to London and the opening of the railway station in 1839 were key to the development of the town. The economic history of Romford is characterised by a shift from agriculture to light industry and then to retail and commerce.

As part of the suburban growth of London throughout the 20th century, Romford significantly expanded and increased in population, becoming a municipal borough in 1937. In 1965, following reform of local government in London, it merged with the Hornchurch Urban District to form the London Borough of Havering, and was incorporated into Greater London. Today, it is one of the largest commercial, retail, entertainment and leisure districts in London and has a well-developed night-time economy.

Romford is first recorded in 1177 as Romfort, which is formed from Old English 'rūm' and 'ford' and means "the wide or spacious ford". The naming of the River Rom is a local 'back-formation' from the name of the town; and the river is elsewhere known as the Beam. The ford most likely existed on the main London to Colchester road where it crossed that river.

The town developed in the Middle Ages on the main road to London and the regionally significant Romford Market was established in 1247. The original site of the town was to the south, in an area known as Oldchurch. It was moved northwards to the present site in the later medieval period to avoid the frequent flooding of the River Rom. The first permanent church on the site of the current Church of St Edward the Confessor was built after permission was granted by Henry IV in 1406. The early history of Romford and the immediate area is agricultural and it is recorded as being the location of a number of mills used to grind corn. The area was a focus of the leather industry from the 15th to the early 19th centuries and there is record of a wide range of industries such as cloth making, weaving, charcoal burning, metal working and brewing. Communications played an important part in its development; the main road to London was maintained by the Middlesex and Essex Turnpike Trust from 1721 and Romford became a coaching town in the 18th century.

Several failed attempts were made in the early 19th century to connect the town to the Thames via a Romford Canal. It was initially intended to terminate at a basin near to the Star Brewery, to transport agricultural products to London and, eventually, to serve growing industrial sites in Romford. A later proposal included an extension to Collier Row, whereby timber from Hainault Forest could be transported to the Thames for use in the Royal Dockyards. Only two miles of canal were constructed and the canal company were unable to reach the town.

The development of the town was accelerated by the opening of the railway station in 1839 which stimulated the local economy and was key to the development of the Star Brewery. Initially Eastern Counties Railway services operated between Mile End and Romford, with extensions to Brentwood and to Shoreditch in 1840. A second station was opened on South Street in 1892 by the London, Tilbury and Southend Railway on the line to Upminster and Grays, giving Romford a rail connection to Tilbury Docks. The two stations were combined into one in 1934. Light industry slowly developed, reaching a peak in the 1970s with a number of factories on the edge of town, such as the Roneo Vickers office machinery company, Colvern manufacturers of wireless components, May's Sheet Metal Works and brush manufacturers Betterware. Suburban expansion increased the population and reinforced Romford's position as a significant regional town centre. The Liberty Shopping Centre was constructed in the 1960s, and has been modernised and supplemented with further shopping centres throughout the town, including The Mercury Mall, opened in 1990; and The Brewery, opened in 2000 on the site of the old Star Brewery.

Romford formed a chapelry in the large ancient parish of Hornchurch in the Becontree hundred of Essex; as well as the town it included the wards of Collier Row, Harold Wood, and Noak Hill. Through ancient custom the area enjoyed special status and a charter in 1465 removed the parish from the Becontree hundred and the county of Essex and it instead formed the independent liberty of Havering governed from a court house in the market place. Over time the vestry of Romford chapelry absorbed the local powers that would usually be held by the parish authorities in Hornchurch and in 1849 Romford became a separate parish within the liberty. Improvement commissioners were set up in 1819 for paving, lighting, watching, and cleansing of the marketplace and main streets. As the town grew this arrangement became ineffective at controlling sanitation and in 1851 a local board of health was set up for the parish; although its area was reduced in 1855 to cover only the town ward. The remainder of the parish became part of the Romford rural sanitary district in 1875. These changes and the introduction of the Romford Poor Law Union in 1836 eroded the powers of the liberty and it was finally abolished in 1892 and reincorporated into Essex.