First Lieutenant Affiliation UNSC Army UNSC Marine Corps UNSC Air Force Higher Rank Captain Lower Rank Second Lieutenant Command Company XO or Platoon Leader Known First Lieutenants Buckman Jake Chapman Melissa McKay Rolf Sorenson Canfield Faison
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First Lieutenant is a junior, company grade commissioned officer rank of the UNSC Marine Corps, Army, and Air Force, equal in rank to Lieutenant, Junior Grade in the UNSC Navy. They usually serve as the XO (executive officer) of a Company, but can be given command of platoons, such as the case of First Lieutenant Melissa McKay in Halo: The Flood.

A Second Lieutenant usually receives a promotion to First Lieutenant after 18 to 24 months service.

In informal settings, First Lieutenants are referred to simply as "Lieutenant" or "LT".

Trivia Edit

• In Halo: Reach, it isn't uncommon to have one or sometimes two First Lieutenants in your fireteams. This is incredibly odd, as it'd be rare to see so many Lieutenants together in the vicinity.

UNSC Defense Force commissioned officer ranks
	O-1	O-2	O-3	O-4	O-5	O-6	O-7	O-8	O-9	O-10	Special
Approximate insignia:
Air Force:	2nd Lt	1st Lt	Capt	Maj	Lt Col	Col	Brig Gen	Maj Gen	Lt Gen	Gen	GOAF
Army:	2LT	1LT	CPT	MAJ	LTC	COL	BG	MG	LTG	GEN	GA
Marine Corps:	2ndLt	1stLt	CPT	Maj	LtCol	Col	BGen	MajGen	LtGen	Gen
Navy:	ENS	LTJG	LT	LCDR	CDR	CAPT	RDML	RADM	VADM	ADM	FADM