title: First officer
text: # First officer
  
  First officer may refer to:
  
  ## Transportation
  
  * Chief mate, the second-in-command (usually) of a merchant ship
  * First officer (aviation) or "co-pilot", the second pilot of a civil aircraft
  
  ## Military
  
  * Executive officer (military), the second-in-command of a naval vessel
  * First officer, the most senior civil service position in the United States Foreign Service
  * First officer, a rank in the Air Transport Auxiliary corresponding to Flight Lieutenant in the Royal Air Force
  * First officer, a rank in the Women's Royal Naval Service corresponding to Lieutenant-Commander in the Royal Navy
  