Local nature reserve or LNR is a designation for nature reserves in the United Kingdom. The designation has its origin in the recommendations of the Wild Life Conservation Special Committee (Conservation of Nature in England and Wales, Command 7122, 1947) which established the framework for nature conservation in the United Kingdom and suggested a national suite of protected areas comprising National Nature Reserves, Conservation Areas (which incorporated suggestions for Sites of Special Scientific Interest), National Parks, Geological Monuments, Local Nature Reserves and Local Educational Nature Reserves. There are now over 1280 LNRs in England, covering almost 40,000 hectares, which range from windswept coastal headlands and ancient woodlands to former inner city railways and long abandoned landfill sites.

The National Parks & Access to the Countryside Act 1949 combined elements of several of these categories in its definition of a nature reserve (Section 15). The hope of the Special Committee was to see sites protected which represented sites of local scientific interest, which could be used by schools for field teaching and experiment, and in which people with no special interest in natural history could "...derive great pleasure from the peaceful contemplation of nature."

A nature reserve (natural reserve, nature preserve, natural preserve) is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research. Nature reserves may be designated by government institutions in some countries, or by private landowners, such as charities and research institutions, regardless of nationality. Nature reserves fall into different IUCN categories depending on the level of protection afforded by local laws.

King Devanampiya Tissa of Sri Lanka established one of the world's earliest wildlife sanctuaries in the 3rd century BC. However, dating back to antiquity there are various cultural practices that equate roughly to the establishment and maintaining of reserved areas for biota including fish, waterfowl and other animals. These would often have a religious underpinning—for example the 'evil forest' areas of West Africa were forbidden to humans, who were threatened with spiritual attack if they went there. Sacred areas taboo from human entry to fishing and are known by many ancient cultures worldwide.