Junior officer

junior officer, company officer or Company-grade officer, refers to the lowest operational commissioned officer category of ranks in a military or paramilitary.

The term, company officer or Company-grade officer, is used more in the army, air force, or marine corps as the ranks of captain, Lieutenant grades and other Subaltern ranks originated from the officers in command of a company or equivalent (cavalry squadron/Troop and Artillery battery).

In many armed forces, a junior officer is specifically a commissioned officer holding rank equivalent to a naval lieutenant, an army captain or a flight lieutenant or below.

In the United States Armed Forces, the term is used by the Navy and the Coast Guard for officers in the ranks of Ensign (O-1), Lieutenant, junior grade (O-2), Lieutenant (O-3) and Lieutenant Commander (O-4).