Hammersmith is a district of West London, England, 4.3 miles (6.9 km) southwest of Charing Cross. It is the administrative centre of the London Borough of Hammersmith and Fulham, and identified in the London Plan as one of 35 major centres in Greater London.

It is bordered by Shepherd's Bush to the north, Kensington to the east, Chiswick to the west, and Fulham to the south, all on the north bank of the River Thames. The area is one of west London's main commercial and employment centres, and has for some decades been a major centre of London's Polish community. It is a major transport hub for west London, with two London Underground stations and a bus and coach station at Hammersmith Broadway.

Hammersmith may mean "(Place with) a hammer smithy or forge", although, in 1839, Thomas Faulkner proposed that the name derived from two 'Saxon' words: the initial Ham from ham and the remainder from hythe, alluding to Hammersmith's riverside location. In 1922, Gover proposed that the prefix was a personal name, Heahmaer or Hæmar, and stating that the suffix must be Anglo-Saxon from -myðe, meaning the junction of two rivers, as Hammersmith Creek merged with the Thames here. The earliest spelling is Hamersmyth in 1294, with alternative spellings of Hameresmithe in 1312, Hamyrsmyth in 1535, and Hammersmith 1675.

The district was a chapelry of the ancient parish of Fulham, but became a fully independent parish in 1631. In the early 1660s, Hammersmith's first parish church, which later became St Paul's, was built by Sir Nicholas Crispe who ran the brickworks in Hammersmith. It contained a monument to Crispe as well as a bronze bust of King Charles I by Hubert Le Sueur. In 1696 Sir Samuel Morland was buried there. The church was completely rebuilt in 1883, but the monument and bust were transferred to the new church.

In 1745, two Scots, James Lee and Lewis Kennedy, established the Vineyard Nursery, over six acres devoted to landscaping plants. During the next hundred and fifty years the nursery introduced many new plants to England, including fuchsia and the standard rose tree.

1804 saw the trial of Francis Smith for the murder of Thomas Millwood in Beaver Lane, Hammersmith. Called the Hammersmith Ghost murder case, it set a unique standard in English legal history.

In 1868, Hammersmith was the name of a parish, and of a suburban district, within the hundred of Ossulstone, in the county of Middlesex. Major industrial sites included the Osram lamp factory at Brook Green, the J. Lyons factory (which at one time employed 30,000 people). During both World Wars, Waring & Gillow's furniture factory, in Cambridge Grove, became the site of aircraft manufacture.

Hammersmith Borough Council had provided the borough with electricity since the early twentieth century from Hammersmith power station. Upon nationalisation of the electricity industry in 1948 ownership passed to the British Electricity Authority and later to the Central Electricity Generating Board. Electricity connections to the national grid rendered the 20 megawatt (MW) coal-fired power station redundant. It closed in 1965; in its final year of operation it delivered 5,462 MWh of electricity to the borough.