The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the International Commission on Zoological Nomenclature (which shares the acronym "ICZN").

Zoological names are written in a standard way so they can be easily recognised. The genus name is first, and must start with a capital, the specific name second, starting with a lower-case letter. This shows the hierarchy between genus and species.

Zoological nomenclature is independent of other system of nomenclature. The scientific name of animals and plants must be different, and the generic name of a plant and an animal may be same, but this system is to be avoided. e.g., the generic name of banyan or fig tree is Ficus and the fig shell (a kind of gastropod shell) is Ficus.

ICZN publishes the International Code of Zoological Nomenclature containing the rules universally accepted as governing the application of scientific names to all organisms which are treated as animals.