Olsenella is a Gram-positive, non-spore-forming, obligate anaerobic and non-motile bacterial genus from the family Atopobiaceae. Olsenella is named after the microbiologist Ingar Olsen. Olsenella bacteria are involved in endodontic infections in humans.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).