Tate Modern is Britain's national gallery of international modern art and forms part of the Tate group (together with Tate Britain, Tate Liverpool, Tate St Ives and Tate Online). It is based in the former Bankside Power Station, in the Bankside area of the London Borough of Southwark. Tate holds the national collection of British art from 1900 to the present day and international modern and contemporary art.

The galleries are housed in the former Bankside Power Station, which was originally designed by Sir Giles Gilbert Scott, the architect of Battersea Power Station, and built in two stages between 1947 and 1963. The power station closed in 1981. In 1992 The Tate Gallery at the British National Art Museum proposed a competition to build a new building for modern art. The purpose for the new building would help with the ever-expanding collection on modern and contemporary art. In 1995 it was announced that Herzog & de Meuron had won the competition with their simple design. The architects decided to reinvent the current building instead of demolishing it. The Tate modern is an example of adaptive reuse, the process of finding new life in old buildings. The building itself still resembles the 20th century factory in style from the outside and that is reflected on the inside by the taupe walls, steel girders and concrete floors. The façade of the building is made out of 4.2 million bricks that are separated by groups of thin vertical windows that help create a dramatic light inside. The history of the site as well as information about the conversion was the basis for a 2008 documentary Architects Herzog and de Meuron: Alchemy of Building & Tate Modern. This challenging conversion work was carried by Carillion. The southern third of the building was retained by the French power company EDF Energy as an electrical substation (in 2006, the company released half of this holding).

Tate Modern currently has seven floors, originally numbered 1 to 7, they were renumbered 0 to 6 in 2012. Levels 0 to 4 contain gallery space.

The main collection displays consist of four wings each taking up approximately half a complete floor of the main building. Each wing has a named theme or subject. Within each wing there are some rooms that change periodically showing different works in keeping with the overall theme or subject of the wing.