For the WWW browsers of the same name, see Netscape Navigator and Mozilla.

A navigator is the person onboard a ship responsible for the navigation of the vessel. On aircraft, the position may also be referred to as a flight officer. The navigator's responsibilities include planning the journey, advising the captain (or pilot) while enroute, and ensuring that hazards or obstacles are avoided.

In the United States Air Force, the Navigator Badge is earned by officers so qualified. Depending on the aircraft and job responsibilities, navigators in the Air Force may also be referred to as Weapon System Officers (WSO) or Electronic Warfare Officers (EWO). In the U.S. Navy and Marine Corps, the equivalent position is known as a Naval Flight Officer (NFO).

Shipborne Navigators in the U.S. Navy must be Surface Warfare qualified.

In the Royal Air Force, the term navigator is always used for the holder of this position in aircraft, including the backseat crew member in two-seater aircraft. Like pilots, navigators are always commissioned officers. They wear the single-wing aircrew brevet, with a capital 'N' in the centre.