First Officer

First Officer is a military rank most commonly found in branches of a country's Naval fleet. The First Officer is the second in command of a military unit after the Captain. They often hold the title Commander or Lieutenant Commander. A common nickname for this position is XO. First Officers appear most frequently in films of the war drama genre, but also appear in science fiction as members of a fictional space fleet.

Appearances

 * Alien
 * Crimson Tide
 * Star Trek
 * Star Trek: The Motion Picture
 * Star Trek II: The Wrath of Khan
 * Star Trek III: The Search for Spock
 * Star Trek IV: The Voyage Home
 * Star Trek V: The Final Frontier
 * Star Trek VI: The Undiscovered Country
 * Star Trek: Generations
 * Star Trek: First Contact
 * Star Trek: Insurrection
 * Star Trek: Nemesis
 * Star Trek: Into Darkness
 * Star Trek Beyond