Staphylococcus xylosus is a species of bacteria belonging to the genus Staphylococcus. It is a Gram-positive bacterium that forms clusters of cells. Like most staphylococcal species, it is coagulase-negative and exists as a commensal on the skin of humans and animals and in the environment. It appears to be far more common in animals than in humans. S. xylosus has very occasionally been identified as a cause of human infection, but in some cases it may have been misidentified.