The London Borough of Islington is a London borough which forms part of Inner London, England. Islington has an estimated population of 215,667. It was formed in 1965, under the London Government Act 1963, by the amalgamation of the metropolitan boroughs of Islington and Finsbury.

Islington was a civil parish and metropolitan borough in London, England. It was an ancient parish within the county of Middlesex, and formed part of The Metropolis from 1855. The parish was transferred to the County of London in 1889 and became a metropolitan borough in 1900. It was amalgamated with the Metropolitan Borough of Finsbury to form the London Borough of Islington in Greater London in 1965.