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 neighbouring boroughs were Finsbury, Hackney, Stoke Newington, Shoreditch, St Pancras.

The parish of St Mary Islington operated as an open vestry.

Because of the reforms directed by the London Government Act 1899, on 1 November 1900 the vestry was abolished and replaced by the Islington Metropolitan Borough Council.

The vestry started work on an electricity supply service at Eden Grove in 1894, which became operational in 1896.

It was a local act parish so it did not come under the Poor Law Amendment Act 1834 and the vestry continued to be responsible for poor relief, instead of a separately elected board of guardians.

Islington Local History Centre holds records of the Metropolitan Borough of Islington, including council and committee minutes, rate books and publications.

[8] Under the Metropolis Management Act 1855 any parish that exceeded 2,000 ratepayers was to be divided into wards; as such the incorporated vestry of St Mary Islington was divided into six wards (electing vestrymen): No.

[9][10] In 1896 as its population had increased the incorporated vestry was re-divided into eleven wards (electing vestrymen): No.

[11] The metropolitan borough was divided into eleven wards for elections: Barnsbury, Canonbury, Highbury, Lower Holloway, Mildmay, St Mary, St Peter, Thornhill, Tollington, Tufnell and Upper Holloway.