**Abstract**

*Staphylococcus aureus* is a pathogen of great importance to clinical and veterinary medicine. Recently, there has been a growing interest in *S. aureus* extracellular vesicles (EVs) in the pathogenesis of this bacterium. Released by living cells into the extracellular milieu, EVs are membranous structures carrying macromolecules such as proteins, nucleic acids, and metabolites. These structures play several physiological roles and are, among others, considered a mechanism of intercellular communication within *S. aureus* populations but also in *trans* kingdom interactions. *S. aureus* EVs were shown to transport important bacterial survival and virulence factors, such as β-lactamases, toxins, and proteins associated with bacterial adherence to host cells, and to trigger the production of cytokines and promote tissue inflammation. In this chapter, we will review the main studies regarding *S. aureus* EVs, including their composition and roles in host-pathogen interactions, and the possible applications of EVs for vaccines and therapy development against staphylococcal infections.

**Keywords:** EV, membrane vesicles, composition, bacterial survival, cargo delivery, immunomodulation, host-pathogen interactions, immunization, vaccine, therapy
