Methanohalophilus is a genus of archaeans in the family Methanosarcinaceae.
The species are strictly anaerobic and live solely through the production of methane, using methyl compounds as substrates. The genus Methanohalophilus contains four moderately halophilic species, Methanohalophilus mahii and Methanohalophilus hillemani cultured from Utah's Great Salt Lake in the United States, Methanohalophilus halophilus isolated from Shark Bay in Australia, and Methanohalophilus portucalensis isolated from a salt pan in Portugal. It also contains Methanohalophilus oregonese, which is alkaliphilic.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).