William Richard Arnold was an American Army officer and prelate of the Roman Catholic Church. He served as the 5th Chief of Chaplains of the United States Army from 1937 to 1945 and Military Delegate of the Armed Forces from 1945 until his death in 1965.

The Chief of Chaplains of the United States Army (CCH) is the chief supervising officer of the U.S. Army Chaplain Corps.. From 1775 to 1920, chaplains were attached to separate units. The Office of the Chief of Chaplains was created by the National Defense Act of 1920 in order to better organize the Chaplaincy. Chaplain William Green Jr. is the current Chief of Chaplains.