The Commendation Medal is a mid-level United States military award which is presented for sustained acts of heroism or meritorious service. For actions where such performance was in direct contact with an enemy force, the Valor device is authorized as an attachment to the decoration.

Each branch of the United States Armed Forces issues its own version of the Commendation Medal, with a fifth version existing for acts of joint military service performed under the Department of Defense.

The Commendation Medal is awarded by local commanders, allowing for a broad interpertation of the criteria for which the medal may be awarded. For instance, in the U.S. Navy and United States Marines, the Commendation Medal is considered a somewhat high decoration reserved for Department level officers, senior CPOs, and as a retirement award. In contrast, the U.S. Army typically authorizes the Commendation Medal for junior officers and enlisted personnel as an end-of-tour award.

The Commendation Medal was originally a ribbon, and was first issued by the Navy and U.S. Coast Guard in 1943. An Army Commendation Ribbon followed in 1945 and, in 1949, the Navy, Coast Guard, and Army Commendation ribbons were renamed as the "Commendation Ribbon with Medal Pendant". By 1960, the Commendation Ribbons had been authorized as full medals, and were subsequently referred to as Commendation Medals.

For additional awards of the Commendation Medal, the Army issues oak leaf clusters and the Navy and Coast Guard furnish gold and silver award stars. The Operational Distinguishing Device is authorized to the Coast Guard Commendation Medal upon approval of the awarding authority.

The U.S. Air Force began issuing its own Commendation Medal in 1958 with additional awards denoted by oak leaf clusters. It was not until 1996 that the "V" device was authorized on the Air Force Commendation Medal. Prior to that time, there was not a Valor distinction in effect for the Air Force Commendation Medal.

The U.S. Marines have always been issued the Navy Commendation Medal and there is not a separate Commendation Medal intended only for Marines. This lack of difference was recognized in 1994 when Secretary of the Navy John H. Dalton changed the name of the Navy Commendation Medal to the Navy and Marine Corps Commendation Medal.

The last of the Commendation Medals is the Joint Service Commendation Medal which was created in 1963. This award is intended for senior service on a joint military staff and is generally considered to be a somewhat high ranking decoration. As such, it is worn above the service Commendation Medals on a military uniform.

The military services also issue an Achievement Medal which is a lesser decoration intended for junior officers and enlisted personnel.