The ICSP, formerly the International Committee on Systematic Bacteriology (ICSB), is the body that oversees the nomenclature of prokaryotes, determines the rules by which prokaryotes are named and whose Judicial Commission issues Opinions concerning taxonomic matters, revisions to the Bacteriological Code, etc.

In the 19th century and the first half of the 20th century, bacteriologists tried to follow the provisions of the Botanical Code of Nomenclature, because bacteria had traditionally been considered fungi, the Schizomycetes. Methods of study were, however, very different. Also, much emphasis had to be put on cultural characteristics, so that type cultures were of critical importance. Type cultures are not permitted under the Botanical Code; therefore, at the First International Congress of Microbiology in Paris in 1930, proposals were made for bacteriology to establish its own Code of Nomenclature. A committee under the able guidance of the American bacteriologist R. E. Buchanan began work on this and, at the Second Congress in London in 1936, a draft Code was presented and placed under the aegis of the International Committee for Bacteriological Nomenclature [later, the International Committee on Systematic Bacteriology (ICSB), and now, the ICSP]. Buchanan condensed the provisions for nomenclature into a few broad principles that are still valid today.

ICSP is a committee under the Bateriology and Applied Microbiology Division of the International Union of Microbiological Societies (IUMS)