The Local Government Act 2001 (No. 37) was enacted by the Oireachtas on 21 July 2001 to reform local government in Ireland. Most of the provisions of the Act came into operation on 1 January 2002. The act was a restatement and amendment of previous legislation, which was centred on the Local Government (Ireland) Act 1898. The 2001 act remains in force, although significantly amended by the Local Government Reform Act 2014.

According to the explanatory memorandum issued before the passing of the Act, its purposes were to:

The act established local government areas based on those already created by previous legislation. The types of areas listed in the act are:

Counties: Identical to the administrative counties established by the Local Government (Ireland) Act 1898 and modified by later legislation. The opportunity was taken to rename Tipperary (North Riding) and Tipperary (South Riding) as North Tipperary and South Tipperary respectively.

Cities: These were the county boroughs created by the 1898 act and later legislation, renamed. All the county boroughs except Galway had previously had the courtesy title of city by charter or letters patent.

Boroughs: The five existing non-county boroughs continued in existence. In addition, it was recognised that Kilkenny could continue to be called a city, in spite of being governed by a borough council and not being a former county borough.

Towns: The remaining town authorities, formerly known as urban districts or towns with town commissioners, were all redesignated as towns.

A council was established for each of the local government areas with the title county council, city council, borough council, or town council (as appropriate).