Berwick-upon-Tweed is the most northerly and second largest constituency in England, with an electorate of some 56,700 living in approximately 1,000 square miles. Although much of the constituency is rural, a majority of people live in market towns such as Alnwick, Berwick, Rothbury and Wooler, and coastal towns such as Amble, Seahouses and Lynemouth. The constituency is bound by the Scottish border to the North and North West and by the North Sea to the East. Its southern border runs along the top of Morpeth and drops down to include the parishes of Belsay, Capheaton and Elsdon.
The constituency formerly included Berwick Borough, Alnwick District and part of Castle Morpeth Borough. With the abolition of the District and Borough Councils in 2008, the entire Berwick-upon-Tweed constituency is now within the Northumberland County Council unitary authority. Conservative Councillors from the Berwick constituency sit with Conservatives from across Northumberland as part of the Northumberland Conservatives County Council political grouping.