A common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, trivial name, trivial epithet, country name, popular name, or farmer's name) is a name in general use within a community; it is often contrasted with the scientific name for the same organism. A so-called "common name" is not always one that is commonly used.

Sometimes common names are created by authorities on one particular subject, in an attempt to make it possible for members of the general public (including interested parties such as fishermen, farmers etc.) to refer to a species of organism without needing to be able to memorise or pronounce the Latinized scientific name. Creating common names can also be an attempt to standardize the use of common names which can sometimes vary a great deal between one part of a country and another as well as between one country and another, even where the same language is spoken in both places.

Some common names form part of a classification of objects. Folk taxonomy, which is a classification of objects using common names, has no formal rules. In contrast, scientific or biological nomenclature is a global system that uniquely denotes particular organisms. Biological nomenclature involves formal rules and periodic international meetings, of the ICBN and the ICZN.