, a gut commensal, is a leading cause of opportunistic infections. Its virulence is linked to its ability to thrive in hostile environments, which includes host-imposed metal starvation. We recently showed that evades iron starvation using five dedicated transporters that collectively scavenge iron from host tissues and other iron-deprived conditions. Interestingly, heme, the most abundant source of iron in the human body, supported growth of a strain lacking all five iron transporters (Δ5Fe). To release iron from heme, many bacterial pathogens utilize heme oxygenase enzymes to degrade the porphyrin that coordinates the iron ion of heme. Although lacks these enzymes, bioinformatics revealed a potential ortholog of the anaerobic heme-degrading enzyme anaerobilin synthase, found in and a few other Gram-negative bacteria. Here, we demonstrated that deletion of OG1RF_RS05575 in (ΔRS05575) or in the Δ5Fe background (Δ5FeΔRS05575) led to intracellular heme accumulation and hypersensitivity under anaerobic conditions, suggesting encodes an anaerobilin synthase, the first of its kind described in Gram-positive bacteria. Additionally, deletion of , either alone or in the Δ5Fe background, impaired colonization in the mouse gastrointestinal tract and virulence in mouse peritonitis and rabbit infective endocarditis models. These results reveal that RS05575 is responsible for anaerobic degradation of heme and identify this relatively new enzyme class as a novel factor in bacterial pathogenesis. Findings from this study are likely to have broad implications, as homologues of are found in other Gram-positive facultative anaerobes.