The Metropolitan Borough of Sefton is a metropolitan borough of Merseyside, England. It was formed on 1 April 1974, by the amalgamation of the county boroughs of Bootle and Southport, the municipal borough of Crosby, the urban districts of Formby and Litherland, and part of West Lancashire Rural District. It consists of a coastal strip of land on the Irish Sea which extends from Southport in the north to Bootle in the south, and an inland part to Maghull in the south-east, bounded by the city of Liverpool to the south, the Metropolitan Borough of Knowsley to the south-east, and West Lancashire to the east.

West Lancashire is a local government district with borough status in Lancashire, England. The council is based in Ormskirk, and the largest town is Skelmersdale. The district borders Fylde to the north, over the Ribble Estuary; South Ribble, Chorley, and Wigan to the east; St Helens, and Knowsley to the south; and Sefton to the south and west.