The study of the gut microbiota by the "culturomics concept" permitted us to isolate, from human stool sample, an unknown anaerobic bacterium within the genusClostridiumfor which we propose the nameClostridium massiliamazoniensesp. nov. It was isolated from the fecal flora of a healthy 49-year-old Brazilian male. Here, we describe the characteristics of this organism and its complete genome sequencing and annotation. Clostridium massiliamazoniensesp. nov., ND2(T)(= CSURP1360 = DSMZ 27309) is a Gram-positive, obligate anaerobic member ofFirmicuteswith a 3,732,600 bp-long genome and a G+C content of 27.6%.