The Marine Corps dress blue uniform is the most formal of a Marine's uniforms, it is often referred to as "Dress Blues", due to the color (as distinguished from the green and khaki service uniforms).

Dress Blue Alphas have long sleeve choker-collar midnight blue (black) outer blouse/tunic, white cover, with all medals and ribbons. A Mameluke Sword may be worn by officers. Staff noncommissioned officers (SNCOs) and non-commissioned officers (NCOs) are authorized to wear the NCO Sword.

Dress Blue Bravos are the same as the Alphas but ribbons and Marksmenship Badges, are worn instead of medals.

Dress Blue Charlies are the same as the Bravos but without the outer blue coat, a khaki long sleeve shirt and khaki necktie are worn instead. Ribbons are normally worn on the shirt with badges being optional unless prescribed.

Dress Blue Deltas are the same as Dress Blue Charlies, but with short sleeve khaki shirt and no tie.

The same trousers, cover (hat) and high gloss black shoes are worn with all versions of dress blues.

Officer blouses do not have the red piping that the enlisted blouses do. Officers also wear a white inner collar, in addition to a while shirt under their blouse. Additionally officers wear metal ranks insignia on their shoulders. Enlisted Marines wear their rank chevron patches on their upper arms.

Enlisted ranks wear a white belt, and different buckles depending on rank. Non-NCOs have a plain brass buckle, NCOs wear a brass buckle with an Eagle Globe and Anchor (EGA), and SNCOs wear a brass buckle with an EGA and leaves. Officer belts are the same color as the blouse. No large buckle is worn.

All ranks wear Eagle Globe and Anchor collar devices on their dress blues blouses. Officer EGAs are gold and silver. Enlisted EGAs are gold. A larger cap device matching the collar devices are worn on the dress blues covers.

General officers wear a two-inch wide scarlet blood stripe down the outer seam of each leg of blue dress trousers/slacks, field and company grade officers wear a 1 1/2-inch wide scarlet stripe down the outer seam of each leg of blue dress trousers/slacks, and staff noncommissioned officers (SNCOs) and non-commissioned officers (NCOs) wear a 1 1/8-inch wide scarlet stripe down the outer seam of each leg of their blue dress trousers / slacks.

The covers also vary with rank. Officer covers have a quatrefoil on the top, enlisted ranks do not. Officer covers also have a red and gold chin strap (black for enlisted), and field grade and general grade officers have gold leaves on the bill.

General officers wear dark blue trousers in the same color as the coat, while lower ranking officers, SNCO's, NCO's and junior enlisted wear medium (sky) blue trousers.