A registered nurse (RN) is a nurse who has graduated from a nursing program and met the requirements outlined by a country, state, province, or similar licensing body to obtain a nursing license. An RN's scope of practice is determined by local legislation governing nurses and is usually regulated by a professional body or council. Registered nurses are employed in various professional settings, often specializing in their field of practice. They may supervise care delivered by other healthcare workers, including enrolled nurses, licensed practical nurses, unlicensed assistive personnel, nursing students, and less-experienced RNs.

Registered nurses often work in hospitals or outpatient facilities, providing hands-on patient care by administering medications, managing intravenous lines, observing and monitoring patients' conditions, maintaining records, and communicating with doctors. They are also relied upon to give direction and supervision to nurses and home health aides.