The United States Army Special Forces (SF), colloquially known as the "Green Berets" due to their distinctive service headgear, is the special operations branch of the United States Army. Although technically an Army branch, the Special Forces operates similarly to a functional area (FA), in that individuals may not join its ranks until having served in another Army branch.

The United States Army has used military berets as headgear with various uniforms beginning in World War II. Since June 14, 2001, a black beret is worn by all U.S. Army troops unless the soldier is approved to wear a different distinctive beret. A maroon beret has been adopted as official headdress by the Airborne forces, a tan beret by the 75th Ranger Regiment, a brown beret by the Security Force Assistance Brigades, and a green beret by the Special Forces.