Interserve plc (LSE: IRV) is an international support services and construction company based in the UK, with revenue of £1.9 billion and a workforce of 50,000 people worldwide. The company is headquartered in Reading, Berkshire and is listed on the London Stock Exchange. It is a constituent of the FTSE 250 Index.

Interserve traces its origins to 1884, when the London and Tilbury Lighterage Company Limited was formed to transfer goods by barge to and from ships. However at an early stage dredging became its main business, and in the 1940s it moved into civil engineering. In 1991 Tilbury acquired RM Douglas, another construction and civil engineering business, and became Tilbury Douglas. Through the 1990s it moved its focus away from property development and housebuilding and into the support services sector. In 2000 it was transferred from the construction sector to the support services sector in the FTSE listing. To reflect this change it renamed itself Interserve in 2001. In 2006 Interserve acquired MacLellan, another support services business. In 2007 the Group acquired a 49 per cent stake in the Qatar-based Madina Group. In 2008 Interserve expanded into new markets in Abu Dhabi and Northern Europe.