First officer
# 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
