The 12th edition of Systema Naturae was the last edition of Systema Naturae to be overseen by its author, Carl Linnaeus. It was published by Laurentius Salvius in Holmia (Stockholm) in three volumes, with parts appearing from 1766 to 1768. It contains many species not covered in the previous edition, the 10th edition which was the starting point for zoological nomenclature.

Systema Naturae is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomenclature, was partially developed by the Bauhin brothers, Gaspard and Johann, Linnaeus was first to use it consistently throughout his book. The first edition was published in 1735. The full title of the 10th edition (1758), which was the most important one, was Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, which appeared in English in 1806 with the title: "A General System of Nature, Through the Three Grand Kingdoms of Animals, Vegetables, and Minerals, Systematically Divided Into their Several Classes, Orders, Genera, Species, and Varieties, with their Habitations, Manners, Economy, Structure and Pecularities".