Desulfohalobium retbaense (Ollivier et al. 1991) is the type species of the polyphyletic genus Desulfohalobium, which comprises, at the time of writing, two species and represents the family Desulfohalobiaceae within the Deltaproteobacteria. D. retbaense is a moderately halophilic sulfate-reducing bacterium, which can utilize H ₂ and a limited range of organic substrates, which are incompletely oxidized to acetate and CO ₂, for growth. The type strain HR ₁₀₀ ^T was isolated from sediments of the hypersaline Retba Lake in Senegal. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the family Desulfohalobiaceae. The 2,909,567 bp genome (one chromosome and a 45,263 bp plasmid) with its 2,552 protein-coding and 57 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.