Major General Ray Wehnes Barker (December 10, 1889 – June 28, 1974) was a United States Army officer of the Allied Forces, and served in the European Theater of Operations during World War II. Barker was a key member of the combined United States-British group, which became known as COSSAC (Chief of Staff to the Supreme Allied Commander). This group planned the Battle of Normandy, codenamed "Operation Overlord", also known as D-Day, which liberated Nazi-occupied France. He served as the Deputy Chief of Staff of the European Theater from 1943 to 1944, and Deputy Chief of Staff for Supreme Headquarters Allied Expeditionary Force (SHAEF).

Ray Barker was born in Elmira, New York and enlisted in the Army first serving with the 15th Cavalry from 1910 to 1913. He was commissioned as an officer in the cavalry in 1913, later participating in the Punitive Expedition into Mexico (Pancho Villa Expedition) from 1916 to 1917. Thereafter, he transferred to the field artillery and accompanied the 13th Field Artillery to France in World War I. He served in the Marne-Vesle and Meuse-Argonne offensives.

In 1928, he graduated from the Command and General Staff School, and in 1940 from the Army War College.

He was the commanding officer of 31st Field Artillery from June 1940 to April 1941. He commanded the 30th Field Artillery from June 1941 until April 1942. After promotion to brigadier general in July 1942, he later became the Deputy Chief of Staff, G-5, of the European Theater from 1943 to 1944, and Deputy Chief of Staff for Supreme Headquarters Allied Expeditionary Force. He was promoted to major general in June 1943. In January 1946 he assumed command of the 78th Infantry Division, headquartered in Berlin, succeeding Major General Edwin P. Parker Jr. He was commander supervising demilitarization of Germany until the deactivation of the 78th in May 1946 (see: commandants of Berlin American Zone). General Barker retired from the military in February 1947.

Two of Barker's notable actions in the Overlord planning involved maintaining American involvement when significant disagreements arose between Americans and British military planners, which could have resulted in withdrawal of America support for the operation.

While Overlord was planned, the expected amount of enemy resistance after aerial and naval bombardment was unclear. Overlord initially stated the land invasion in France could not succeed against more than twelve divisions of enemy troops; Barker predicted this would make the invasion unpalatable and risk American opposition. Barker's concern was correct and lead to opposition from the Joint Chiefs in America. After further discussion and clarifications from Barker, the America government's support was accomplished.

Tensions between Americans and British governments again arose due to how involved a battlefield commander should be in such an invasion, particularly when a multi-national force is commanded by a single battlefield commander. Barker as the acting Chief of Staff to the Supreme Allied Commander, was able to solidify agreement between the countries of how this should be handled.

His decorations included the Distinguished Service Medal, Legion of Merit, Bronze Star Medal, and Soldier's Medal.