葡萄球菌（学名：Staphylococcus）是一群革兰氏染色阳性球菌，因常常堆聚成葡萄串状而得名。在生物学分类上，葡萄球菌是芽孢杆菌目的一个属。多数葡萄球菌为非致病菌，少数可致病。有些菌种为人类皮肤和黏膜上的正常菌种，不会产生芽孢，夹膜不明显，无鞭毛和运动性。

代表种有金黄色葡萄球菌（S. aureus）、白色葡萄球菌（S. albus）、柠檬色葡萄球菌（S. citreus）等。

Staphylococcus (from the Greek:σταφυλή, staphylē, "grape" and κόκκος, kókkos, "granule") is a genus of Gram-positive bacteria. Under the microscope, they appear round (cocci), and form in grape-like clusters.

The Staphylococcus genus includes at least 40 species. Of these, nine have two subspecies, one has three subspecies, and one has four subspecies. Most are harmless and reside normally on the skin and mucous membranes of humans and other organisms. Found worldwide, they are a small component of soil microbial flora.