The Citigroup Centre is a building complex in London. It houses Citigroup's EMEA headquarters and is located in Canary Wharf in the city's Docklands. The centre provides 170,000 square metres (1,800,000 sq ft) of floor space across two buildings - 33 Canada Square and 25 Canada Square, and houses the bulk of Citi's UK employee base. The buildings were separated in 2023, prior to a £100m renovation of 25 Canada square.

25 Canada Square, stands at 200 metres (656 ft) and, upon its completion in 2001, became the second-tallest building in the United Kingdom (only behind One Canada Square). Designed by César Pelli & Associates, construction of the 45-storey tower - undertaken by Canary Wharf Contractors - began in 1998 and was completed in 2001, with Citigroup leasing the building from the outset. The building was bought by RBS in 2004 along with 5 Canada Square (leased to Bank of America) for $1.12 billion. Subsequently, on 2 July 2007, 25 Canada Square was individually sold to a joint venture between Quinlan Private and PropInvest for £1 billion (US$2 billion). Citigroup paid £46.5 million a year in rent for the tower, generating a yield of 4.6% to the owners. Citi later bought the tower in £1bn in 2019. The east facing side of 25 Canada Square up to level 40 is configured for use by tenants.

33 Canada Square, is the smaller of the two buildings in the complex, designed by Norman Foster and completed in 1999, two years before its neighbour. At 105 metres (344 ft) tall, the building is made up of eighteen floors. The building is owned by Citigroup, and was built before the completion of the Jubilee line extension in late 1999.

In addition to main entrances from both Canada Square and Upper Bank Street, Citigroup Centre is also accessible via underground walkways from Canada Place shopping mall and Canary Wharf London Underground station - served by the Jubilee line. The Centre is also close to DLR stations Canary Wharf and Heron Quays, which provide connections with the City, London City Airport and surrounding areas.

In 2022, plans were announced to refurbish the building. The £100m redevelopment would incorporate holistic spaces such as parent rooms, prayer rooms and green spaces including a winter garden.

• List of tallest buildings and structures in London
• List of tallest buildings and structures in Great Britain