A novel strain of a Gram-stain negative, non-motile, non-spore forming rod-shaped, obligate anaerobic bacterium, designated AT11T, was isolated from a stool sample of a morbidly obese woman living in Marseille, France. This bacterium was characterized using biochemical, chemotaxonomic, and phylogenetic methods. The 16S rRNA gene sequence analysis showed that strain AT11T had a 97.8% nucleotide sequence similarity with Eisenbergiella tayi strain B086562T, the closest species with standing in nomenclature. The major cellular fatty acids of the novel isolate were C16:0 followed by saturated or unsaturated C18 fatty acids (C18:1n9, C18:1n5 and C18:0). The draft genome of strain AT11T is 7,114,554 bp long with 48% G+C content. 6176 genes were predicted, including 6114 protein-coding genes and 62 were RNAs (with 2 5S rRNA genes, two 16S rRNA genes, two 23S rRNA genes, and 56 tRNA genes). The digital DNA-DNA hybridization (dDDH) relatedness between the new isolate and E. tayi strain B086562T was 23.1% ± 2.2. Based on the phenotypic, chemotaxonomic, genomic, and phylogenetic characteristics, Eisenbergiella massiliensis sp. nov., is proposed. The type strain is AT11T (= DSM 100838T = CSUR P2478T).