Junior officer, company officer or company grade officer refers to the lowest operational commissioned officer category of ranks in a military or paramilitary organization, ranking above non-commissioned officers and below senior officers.
The terms company officer or company-grade officer are 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 the United States Armed Forces, the term junior officer 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).
The U.S. commissioned officer corps is divided into ten pay grades (O-1 through O-10). Officers in pay grades O-1 through O-3 are considered company grade officers. In the Army, Marine Corps and Air Force, these pay grades correspond to the ranks of second lieutenant (O-1), first lieutenant (O-2), and captain (O-3), and in the Navy, these pay grades correspond to ensign (O-1), lieutenant (junior grade) (O-2), and lieutenant (O-3). Officers in pay grades O-4 through O-6 are considered field grade officers, with the exception of the Navy, as an O-4 is still considered a junior officer. In the Army, Marine Corps, and Air Force, these pay grades correspond to the ranks of major (O-4), lieutenant colonel (O-5), and colonel (O-6), and in the Navy, lieutenant commander, commander, and captain. The highest four pay grades are reserved for general officers in the Army, Marine Corps and Air Force and flag officers in the Navy. The ranks associated with each pay grade are as follows: in the Army, Marine Corps and Air Force, brigadier general (O-7), major general (O-8), lieutenant general (O-9) and general (O-10); in the Navy, rear admiral (lower half), rear admiral, vice admiral and admiral.
- Enlisted rank
- Officer (armed forces)
- Warrant officer
- "Commissioned Officers". Ranks. CanadianSoldiers.com. Retrieved 31 January 2013.
- "Captain". Ranks. canadiansoldiers.com. Retrieved 4 February 2013.
- "Lieutenant". Ranks. canadiansoldiers.com. Retrieved 4 February 2013.
- "company officer". Free Merriam-Webster Dictionary. Merriam-Webster, Inc. Retrieved 4 February 2013.