Corporal
Corporal was a traditional infantry enlisted military rank, the equivalent of which was used by the service organizations of many civilizations, which typically ranked below sergeant and above lance corporal. In comparison to naval ranking systems, this rank was marginally equivalent to the naval petty officer or yeoman ranks.

The rank of corporal existed on Earth for several hundred years. In 1986, the rank was a junior enlisted grade of the United States Army. () 

This grade existed in some form in many rank arrangements, such United Earth MACOs in the 2150s. Some personnel who held this rank were given operational authority, such as Corporal McKenzie who was promoted to CO on the recommendation of her superior officer, Major Hayes, before he succumbed to mortal injuries sustained in rescuing Ensign Hoshi Sato. ()

In 2154, the rank existed in some capacity within the Starfleet, most notably at the Earth embassy on . ()

The rank was also used on Ekos in 2268 by the Ekosian SS. A corporal was guarding the main entrance to the Ekosian Chancellery when Daras arrived to hear a special speech given by John Gill. Daras told the corporal to "smile" for the cameras of the Führer's Special Documentary Corps, who were in fact a special team of Zeon and  crewmembers who were attempting to infiltrate the chancellery. () 

During the Q Civil War, the rescue of Q and Kathryn Janeway from a Confederate Army camp was conducted by several members of the  crew dressed as Union Army infantry, including Harry Kim, who wore the rank insignia of a Union corporal. ()

List of corporals 
Named
 Askwith (Starfleet)
  (MACO)
  (MACO)
  (MACO)
  (MACO)
  (MACO)
  (MACO CO, after death of Major Hayes)
 O'Malley (MACO)
  (MACO)
  (MACO)
  (MACO)
  (MACO) (mirror universe)

Unnamed
 Ekosian corporal 1 (Ekosian Schutzstaffel)
 Human corporal (United States Army)
 Holographic SS radio operator (German SS)

External link 
 

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Military ranks