Wanstead Flats is the southernmost portion of Epping Forest, in Leytonstone and Wanstead, London. The flats and by extension the forest ends at Forest Gate directly to the south. It now falls wholly within the boundaries of the London Boroughs of Redbridge and Waltham Forest, though until 1994 two parts of it were in the London Borough of Newham: one of these was the section between Aldersbrook Road and Capel Road east of the junction between Aldersbrook Road and St Margaret's Road, whilst the other was the strip running along Capel Road between its junctions with Centre Road and Ridley Road. As part of Epping Forest, the Flats is managed by the City of London Corporation.

Epping Forest is a 2,400-hectare (5,900-acre) area of ancient woodland, and other established habitats, which straddles the border between Greater London and Essex. The main body of the forest stretches from Epping in the north, to Chingford on the edge of the London built-up area. South of Chingford the forest narrows, and forms a green corridor that extends deep into East London, as far as Forest Gate; the forest's position gives rise to its nickname, the Cockney Paradise. It is the largest forest in London.