Olympia London, sometimes referred to as the Olympia Exhibition Centre, is an exhibition centre, event space and conference centre in West Kensington, in the London Borough of Hammersmith and Fulham, London, England. A range of international trade and consumer exhibitions, conferences and sporting events are staged at the venue.
 There is an adjacent railway station at Kensington (Olympia) which is both a London Overground station, and a London Underground station. The direct District Line spur to the station only runs at weekends.
 The complex first opened in 1886.
 The Grand Hall and Pillar Hall were completed in 1885. The National Hall annexe was completed in 1923, and in 1930 the Empire Hall was added.
 After World War II, the West London exhibition hall was in single ownership with the larger nearby Earls Court Exhibition Centre. The latter was built in the 1930s as a rival to Olympia.
 In 2008, ownership of the two venues passed from P&O to Capco Plc which sold it off as a going concern, while Earls Court was being demolished in 2014 as part of an ambitious regeneration scheme to create more luxury housing.
In 2012, Olympia celebrated 125 years of events by commissioning British artists Peter Blake, Rob Ryan, Sanna Annukka and Paul Hicks to create their interpretations of the venues.
 In January 2013, a £40 million investment was completed and the company re-launched with a new brand; subsequently the business was awarded the Best Marketing Campaign at the Exhibition News Awards 2014.
 In May 2021, demolition work started at the site as part of a significant overhaul of the complex, which includes new construction and refurbishment of listed historic aspects.
 Olympia was originally conceived in the early 1880s as the National Agricultural Hall, a larger version of the Royal Agricultural Hall  (1861–62, Grade II) in Islington. The project of building a National Agricultural Hall was conceived by Edwyn Sherard Burnaby (1830-1883), MP for Leicestershire North, who primarily wanted to see shows such as the military Royal Tournament, held at the Royal Agricultural Hall in Islington since 1880, staged on a much larger scale and made more easily accessible by railway from across London and the rest of the country.
 The site chosen was a former market garden in West Kensington, immediately adjacent to Addison Road station, already a major passenger station on the West London Railway, which became an important method of transport for visitors to Olympia. The building was branded as Olympia even before it opened as its commercial rationale quickly evolved beyond the staging of agricultural or military shows into an open-ended exploitation of what was the largest such venue in England at the time. Intended as a large indoor space for exhibitions, tournaments, sporting competitions and entertainments of various kinds, the building followed in the tradition of large-scale exhibition halls popularised by the Great Exhibition in 1851, the inspiration for various imitators in London, elsewhere in the United Kingdom, and around the world.
 The Olympia Exhibition Centre consists of:
 In 2003, The Grand Hall and the Pillar Hall of 1885, designed by Coe and Edmeston, were given historic status, listed at Grade II* for their historic interest and their architectural value. Olympia Central, a large concrete building in the Moderne architectural style was not fully listed due to the number of changes made through the 20th Century, however its distinctive façade was listed.
 In May 2021, demolition started on the non-listed parts of Olympia London as part of a comprehensive mix-used redevelopment of the complex by its current owners, while still retaining significant exhibition space. In May 2021, the Olympia Theatre was announced with 1,575 seats, making it the largest new theatre in London since the completion of the National Theatre in 1976. This is in addition to previously announced and consented hotels, rehearsal spaces, cinemas, 4,000 seat music venue, retail, dining and public spaces. The major 21st Century redevelopment of Olympia is within the same site boundaries as the historic event spaces.
 Olympia Hall was the venue for the Aga Khan's UK Padhramni from 1–7 September 1979. Olympia Hall was transformed to a solemn place of prayer clad in red and green textile and the Imamat crest adorned with fresh flowers.
 Olympia Hall was the venue for the Aga Khan's silver jubilee visit to UK on 5 July 1983. The darbar was attended by members of the Imamat family.