Municipal boroughs were a type of local government district which existed in England and Wales between 1835 and 1974, in Northern Ireland from 1840 to 1973 and in the Republic of Ireland from 1840 to 2002. There were similar structures in Scotland from 1833 to 1975.

There were boroughs in England and Wales since the middle ages. In 1833 a Royal Commission investigated them. 263 towns in England and Wales had some form of corporation. The Municipal Corporations Act 1835 reformed the government of towns. It set up municipal boroughs. They each had an elected town council, with a mayor, aldermen and councillors. To vote in the elections voters had to own property in the area. The councillors were directly elected for a three-year term, If there were more than 6,000 people the area was divided into wards with separate elections held in each ward each year. There were then 178 municipal boroughs.^[1]

The smaller boroughs which had not been reformed were mostly abolished in the 1880s by the Municipal Corporations Act 1883, except for the City of London Corporation.^[2]

The Local Government Act 1888 created county councils across England and Wales. Boroughs were divided into two sorts, with some becoming county boroughs which were entirely self-governing and independent from county councils.

There were over 200 municipal boroughs in 1974 when they were abolished by the Local Government Act 1972. In England, they were replaced by metropolitan or non-metropolitan districts and in Wales by districts.

Similar things happened in Ireland under British rule. The Local Government (Ireland) Act 1898 set up the six largest cities - Belfast, Cork, Dublin, Limerick, Derry and Waterford as county boroughs.