A nurse anesthetist (also CRNA or nurse anesthesiologist) is an advanced practice nurse who administers anesthesia for surgery or other medical procedures. They are involved in the administration of anesthesia in a majority of countries, with varying levels of autonomy.

A survey published in 1996 reported that there were 107 countries where nurses administer anesthesia in some form, and a further nine countries where nurses act as assistants in the administration of anesthesia. Depending on the local system of healthcare, they participate only during the operation itself, or may also be involved before and after (for preanesthetic assessment and immediate postoperative management). In some localities, nurse anesthetists provide anesthesia to patients independently; in others they do so under the supervision of anesthesiologists.

The International Federation of Nurse Anesthetists was established in 1989 as a forum for developing standards of education, practice, and a code of ethics. Delegates from 35 member countries participate in a World Congress every few years.