The UN List is the official list of protected areas provided by the United Nations. It is produced by UNEP-WCMC working in close collaboration with the IUCN World Commission on Protected Areas (WCPA). Information is provided by national authorities, secretariats of international conventions and programmes from other organisations to the WDPA.

The United Nations List of National Parks and Equivalent Reserves was drawn up at the request of the United Nations following a resolution adopted by the General Assembly at its Sixteenth Session in December 1962 on "Economic Development and Nature Conservation". This resolution served to endorse an earlier resolution (No. 713) of the 27th Session of the UN Economic and Social Council held in 1959, which recognized National Parks and Equivalent Reserves as an important factor in the wise use of natural resources, and led to the compilation of the first global List of National Parks and Equivalent Reserves. IUCN was instrumental in the preparation of the two resolutions, and has since had primary responsibility for the compilation and maintenance of the list. The UN List is now prepared jointly by the IUCN WCPA and UNEP-WCMC. From 1962 to 2003, 13 editions of the UN List have been produced.

The format and content of the 2003 UN List was a significant departure from the previous editions that have been produced. The UN List has been an evolving process since its inception in 1962, moving from the iconic national park "roll of honour" concept that characterised the earlier UN Lists to one that reflects the range of protected area objectives and values relevant to the late 20th and early 21st century. Criteria and definitions for inclusion have changed, although both the 1997 and 2003 UN Lists use the IUCN Protected Area Management Categories system as the basis for analysis. Globally, the numbers of protected areas have increased substantially, and their conservation values and role in the provision of ecosystem services and sustainable development has broadened considerably.

In all previous editions of the UN List, criteria for inclusion have focused on specific definitions of protected areas, a minimum size and, since the 1982 edition, the UN List has only included those sites which can be designated into the IUCN categorisation scheme. With respect to these criteria, it was decided in the 2003 edition to include all protected areas that meet the IUCN definition of a protected area, regardless of size and whether or not they have been assigned an IUCN category. Their omission would have significantly under-represented the efforts that have been made by many countries to establish protected areas.