The principal areas of Wales, comprising the counties and county boroughs of Wales, are a form of subdivision in Wales. There are currently 22 principal areas in Wales, and they were established in 1996. They are a single-tier form of local government, each governed by a principal council. They replaced the previous two-tier system of eight counties and 37 districts that were in place in Wales from 1974 to 1996.

For local government, Wales is divided into 22 sub-divisions collectively called "principal areas" in the 1994 act. They may be styled as either a "county" or a "county borough". Each principal area is overseen by a "principal council", which may also adopt their principal area style, being called a "county council" (Welsh: cyngor sir) or a "county borough council" (Welsh: cyngor bwrdeistref sirol).

The basic framework of local government and specifically a council's constitution and general powers were set out in the Local Government Act 1972, which simplified the existing local governing structure in Wales that existed prior. The later Local Government (Wales) Act 1994 restructured local government, by significantly amending the previous act. The councils of the principal areas are generally supervised by the Welsh Government.

The names of the principal areas, in both English and Welsh, are set out in the 1994 amended version of the 1972 act, under Schedule 4. Section 74 of the 1972 act allows principal councils to change their names, if there is a two-third majority support for such in a specially convened meeting. Since their establishment, multiple councils have pursued a name change. Any notice of a name change has to be submitted to the Welsh Ministers and the Local Democracy and Boundary Commission for Wales. The 1972 changes were enacted in 1974 by the then Conservative administration.

The principal areas' councils are unitary authorities, and are sub-divided into communities and electoral wards.

Some of the principal areas have county borough status, a largely historical status that reflects their historical existence as major population centres. The eleven county boroughs of Wales are Blaenau Gwent, Bridgend, Caerphilly, Conwy, Merthyr Tydfil, Neath Port Talbot, Newport, Rhondda Cynon Taf, Torfaen, Vale of Glamorgan and Wrexham. County borough status does not award any different rights compared to the other counties. The 1994 act stated they should not be treated as a "borough" as defined by earlier legislation.

The other eleven have county status, and are styled as "counties".

The principal areas' boundaries are made up of its electoral wards, and the average number of electoral wards in a principal area is 40.