Merseyside is a metropolitan county in the North West of England, with a population of around 1,365,900. Taking its name from the River Mersey, the title “Merseyside” came into existence as a metropolitan county in 1974, after the passage of the Local Government Act 1972, and the county consists of five metropolitan boroughs adjoining the Mersey Estuary, including the City of Liverpool.

Merseyside County Council was abolished in 1986, and so its districts (the metropolitan boroughs) are now effectively unitary authorities. However, the metropolitan county continues to exist in law and as a geographic frame of reference.

Merseyside is divided into two parts by the Mersey Estuary: the Metropolitan borough of Wirral is located to the west of the estuary on the Wirral Peninsula; the rest of the county is located on the eastern side of the estuary. The east boroughs of Merseyside border Lancashire to the North and Greater Manchester to the East, and both parts of Merseyside, west and east of the estuary, border Cheshire to the south.

Merseyside is an amalgamation of 22 former local government districts, including six county boroughs, and two municipal boroughs.