Local government in Wales is primarily undertaken by the twenty-two principal councils. The councils are unitary authorities, meaning they are responsible for providing local government services within their principal area, including education, social work, environmental protection, and most highway maintenance. The principal areas are divided into communities, most of which have an elected community council. The services provided by community councils vary, but they will typically maintain public spaces and facilities. Local councils in Wales are elected; the most recent local elections in Wales took place in 2022, and the next are due to take place in 2027.

Local government is generally supervised by the (devolved) Welsh Ministers, who allocate funding of the majority of local government yearly revenue and capital settlements. The Government of Wales Act 2006 gave the Welsh Ministers the responsibility of setting up a scheme on how they are to propose and exercise their functions for the promotion and sustainability of Welsh local government.

Like councils throughout the UK, Welsh councils are composed of elected councillors and local government elections normally take place every four years. The Wales Act 2017 prevents local government elections from taking place in the same year as elections to the Senedd, meaning the May 2021 local elections to were postponed to May 2022. There are currently 22 principal areas (styled as a county or a county borough) in Wales, with the current configuration established in the Local Government (Wales) Act 1994, enacted on 1 April 1996, while the framework was established earlier in the Local Government Act 1972. Like community councils, they are composed of councillors.

Councils are required by law to hold annual general meetings, including after their election. In this meeting the council's chair or presiding member would be elected. Some councils also elect an individual to perform civic and ceremonial duties, usually known as a mayor and deputy mayor, with some styled as lord mayor.

Council decisions may be taken by the entire council, some legally defined committees (e.g. scrutiny, audit, licensing, planning and governance committees), or by the council's executive, largely made up of a majority of councillors. All principal councils in Wales have an executive leader and cabinet, although directly-elected mayor model can be adopted by a council if there is public support through a referendum. Some decisions are required by law to be voted on by the entire council, such as the council budget and the amount of council tax. Most committees must be "politically balanced", proportionally representative of the council's political make up. Councils in Wales cannot operate a "committee" system as done in England.

All principal councils have to prepare and agree on a council constitution by law. It would also have to be kept up to date, published electronically, and revised when amended.

The principal councils of Wales, have responsibility and deliver over 700 local government services. These include:

The 22 principal councils of Wales are: