These prokaryotes are thermophilic sulphur-dependent organisms related to the genera Sulfolobus, Pyrodictium and Desulfurococcus.

Like other hyperthermophiles, Thermoproteus represents a living example of some of Earth's earliest organisms, located at the base of the Archaea.

[2] The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [3] and National Center for Biotechnology Information (NCBI)[4] T. tenax Zillig & Stetter 1982 T. thermophilus Yim et al. 2015 T. uzoniensis Bonch-Osmolovskaya et al. 2001 T. tenax T. uzoniensis A significant amount of research has been done on the metabolism of Thermoproteus and other hyperthermophiles as well.

The lipids' unsaturations are generally conjugated (as opposed to the unconjugation found in Bacteria and Eukaryota).

Members of Thermoproteus are found in acidic hot springs and water holes; they have been isolated in these habitats in Iceland, Italy, North America, New Zealand, the Azores, and Indonesia.