Wikispecies è un progetto della Wikimedia Foundation che è stato lanciato il 5 settembre 2004. I dettagli sulla fondazione del progetto sono disponibili su FAQ. Esso è multilingua e non ha varianti linguistiche come Commons.
Wikispecies is intended to be a free taxonomic reference and directory, for both the scientist and the average reader. It exists as a database aggregating the classifications and genetic family tree of all species of life, from all six kingdoms. However, its content on life differs from the articles on Wikipedia in that actual discussion is omitted in Wikispecies and is instead strictly replaced by the taxonomic roots of the species at hand. A febbraio del 2021 esistevano già più di 750 000 articoli di specie su Wikispecies.
The need for a project such as Wikispecies is evidenced by the lack of a formal center for taxonomic classification; a major problem for biology in the past and today has been the disorderly nature of man's species classification pool. Having had no proper centrality for classification, problems have arisen in the multiple classification of the same species, twice, three times or even more. The success of Wikipedia in the maintaining and harbouring of vast amounts of knowledge has demonstrated that an online aggregator is truly the best tool for the kind of species directory that the biological community so needs.