Second Lieutenant is a junior Company Grade Commissioned officer rank of the UNSC Marine Corps, UNSC Army, and UNSC Air Force; it is the lowest commissioned officer rank and is equal in rank to Ensign in the UNSC Navy. Second Lieutenants are given command of platoons, such as the case of Second Lieutenant Oros in Halo: The Flood.
In informal settings, Second Lieutenants are referred to simply as "Lieutenant" or "LT".
|UNSC Defense Force commissioned officer ranks|
|Air Force:||2nd Lt||1st Lt||Capt||Maj||Lt Col||Col||Brig Gen||Maj Gen||Lt Gen||Gen||GOAF|