The United States Marine Corps' alpha service uniform is the most formal combination of the service's khaki day-to-day office dress. Because the Marine Corps puts such a high emphasis on its tradition and the appearance of its personnel in uniform, the wear of alpha service dress is highly regulated. These regulations, listed in Marine Corps Order (MCO), P1020.34, dictate everything from how the uniform should be worn to what occasions it should be used for.

The USMC alpha service uniform is slated for use during events such as parades, social events and ceremonies in addition to a number of military-focused occasions. In the course of military duty, alpha service dress should be worn when officially reporting for duty, when traveling to The White House on official business, when hosting other military officers and dignitaries or acting as a member of a court-martial. It should not, however, be worn at other formal or semi-formal events.

The male alpha service uniform consists of a long-sleeve, button-up khaki shirt tucked into a pair of pressed brown slacks with a khaki belt. Men are required to wear black, carefully shined dress shoes with the uniform and a khaki neck tie and brown military style hat. The distinguishing part of the alpha uniform, however, is the required brown coat that must be worn fully buttoned and belted. The coat should be semi-form fitting with roughly two inches of space in the chest and one inch at the waist. A coat that is properly fitted should ride up and down the body freely when the Marine raises and lowers his arms.

The female alpha uniform is comprised of a khaki-colored, long-sleeve princess cut shirt with a brown skirt that extends down to the knees. This shirt does not need to be tucked in. Note that females are authorized to wear brown slacks if they so desire. Women should also wear full-length nylon hose with the uniform along with black, shined female dress shoes and a brown hat. The female coat should be buttoned up to the top and fit securely, but not too tightly across the bust and should move freely with natural movement. Female Marines are also authorized to wear a brown handbag with the uniform.