A navigator is the person on board a ship or aircraft responsible for its navigation. The navigator's primary responsibility is to be aware of ship or aircraft position at all times. Responsibilities include planning the journey, advising the Captain or aircraft Commander of estimated timing to destinations while en route, and ensuring hazards are avoided. The navigator is in charge of maintaining the aircraft or ship's nautical charts, nautical publications, and navigational equipment, and generally has responsibility for meteorological equipment and communications.

In the world's air forces, modern navigators are frequently tasked with weapon systems employment and co-pilot type duties depending on the type, model and series of aircraft. In the U.S. Air Force, the aeronautical rating of Navigator has been augmented by addition of the Combat Systems Officer, while in the U.S. Navy and U.S. Marine Corps, those officers formerly called Navigators or Naval Aviation Observers have been known as Naval Flight Officers since the mid-1960s. USAF Navigators/Combat Systems Officers and USN/USMC Naval Flight Officers must be Basic Mission Qualified in their aircraft, or fly with an Instructor Navigator or Instructor NFO to provide the necessary training for their duties.

Shipborne navigators in the U.S. Navy are normally Surface Warfare Officer qualified with the exception of Naval Aviators and Naval Flight Officers assigned to Ship's Navigator billets aboard aircraft carriers and large deck amphibious assault ships and who have been qualified at a level equal to Surface Warfare Officers. U.S. Coast Guard officers that are shipboard navigators are normally Cutter qualified at a level analogous to the USN officers previously mentioned. Quartermasters are the Navigator's enlisted assistants and perform most of the technical navigation duties.

Aboard ships in the Merchant Marine and Merchant Navy, the Second Mate is generally the (senior) Navigator.

With the advent of GPS, the effort required to accurately determine one's position has decreased by orders of magnitude, so the entire field has experienced a revolutionary transition since the 1990s with traditional navigation tasks being phased out. The U.S. Air Force and U.S. Navy, for instance, no longer teach aviators how to do celestial navigation.

Read more about Navigator:  Nautical Charts, Nautical Publications, Mission/Passage Planning, Navigational Equipment