Senior officer

Field grade officer's quarters, next to the ceremonial parade ground of Fort Bliss, Texas

A field officer or field grade officer is an army, Marine, or air force commissioned officer senior in rank to a company officer but junior to a general officer.

Historically, a regiment or battalion's field officers made up its command element.

Today, a field officer is a major, lieutenant colonel, or a colonel. The British Army, (in which these officers are called officers of field rank, not field grade) and some others in the Commonwealth (including the Australian Army and New Zealand Army), also include the brigadier in this category: the equivalent in other armies is a general officer (the brigadier general).

In the Canadian Forces, the equivalent of field officers are senior officers (French: Officiers supérieurs); they include the army and air force ranks of Major, Lieutenant-Colonel, and Colonel, and the naval ranks of Lieutenant-Commander, Commander, and Captain.