Oscar D. Yarbrough was born on 30 December 1905, in Lafayette, Alabama, son of the late Dr. C. S. Yarbrough and Mrs. (Bertha Grout) Yarbrough. He attended Lee County High School, Auburn Alabama; Marion Military Institute, Marion, Alabama; Gulf Coast Military Academy, Gulfport, Mississippi; and Alabama Polytechnic Institute at Auburn; and received his Bachelor of Science degree from the University of Maryland, Baltimore, Maryland, in 1928. During his college years he played baseball, football, and basketball.
He served as Second Lieutenant in the US Army Reserve from 1927 to 1929, and in June 1929, entered the US Navy as a Lieutenant (jg) in the Medical Corps, having status as a graduate of Medical School and internship at Baltimore City Hospital, Baltimore, Maryland. Through subsequent promotions he attained the rank of Captain to date from 1 August 1943.
Beginning his naval service in June 1929 at the Naval Hospital, Naval Air Station, Pensacola, Florida, he was ordered in August 1930 to the Naval Medical School, Washington, DC, for duty and instruction until April 1931. During that period he had temporary additional duty at the Naval Academy, Annapolis, Maryland. On 27 April 1931, he reported to the US Naval Dispensary, Navy Department, Washington, DC, where he was on duty until 21 August 1932.
After a tour of duty with Submarine Squadron Three, based on Coco Solo, Canal Zone, he returned in August 1934 to Washington, for five years’ duty with the Experimental Diving Unit at the Naval Gun Factory, where he also completed the Naval Medical School basic course in Deep Sea Diving and Submarine Medicine. While in that assignment he was ordered to and served as Senior Medical Officer of the Squalus Salvage Unit at Portsmouth, New Hampshire, in the summer of 1939, during the salvage and rescue operation on this ill-fated vessel. For meritorious service in that assignment he received Letters of Commendation from the Commander in Chief and Commander, Squalus US Salvage Unit.
Duty with Submarine Escape Training Tank at the Submarine Escape training Tank at the Submarine Base, Pearl Harbor, and with Submarine Squadron Four, based there from August 1939 until September 1941 was followed by a second tour of duty with Experimental Diving Unit, Naval Gun Factory, Washington, ending in June 1944. Early in World War II he reported to USS Lark, submarine rescue vessel, for additional duty in connection with the salvage of sunken German submarines and later transferred to the HMS Beddington, British submarine rescue vessel, for similar duty. He also served with the Commander, Naval Forces, Europe, in connection with undersea warfare operations in the United Kingdom. He was designated a Submariner on 8 June 1944.
Leaving European waters for the Pacific, he reported in July 1944 to the staff of Commander, Submarine Force, Pacific Fleet, at Pearl Harbor, Territory of Hawaii. During the period of his assignment as Force Medical Officer, he was awarded the Bronze Star Medal for “meritorious service as Medical Officer of the Submarine Force, Pacific Fleet, and Senior Medical Officer of the U.S. Naval Submarine Base, Pearl Harbor, in connection with operations against enemy Japanese forces in the Pacific Ocean Area from July 10, 1944 to September 2, 1945…” The citation further points out that “Captain Yarbrough maintained the health of submarine personnel at a high standard, thereby permitting them to perform their individual duties at the greatest possible consistency…”
Returning to the United States, he reported in April 1946 to the Bureau of Medicine and Surgery, Navy Department, Washington, DC, where he was assigned duty as Chief of the Submarine Medicine Division and head of the Submarine and Diving Branch of the Research Division. During this assignment, he also served as Liaison Officer, Bureau of Medicine and Surgery and Bureau of Ships. He continued to serve in that capacity until June 1951, when he became Force Medical Officer on the staff of Commander, Submarine Force, US Pacific Fleet. In April 1953, he was ordered to the Navy Department to serve in the Bureau of Medicine and Surgery as Director of the Research Division and in August 1957 was designated Assistant Chief of the Bureau of Medicine and Surgery for Research and Military Medical Specialties.
In addition to the Bronze Star Medal, Captain Yarbrough had the American Defense Service Medal, Base Clasp and star; American Campaign Medal; the European-African-Middle Eastern Campaign Medal; the Asiatic-Pacific Campaign Medal; The World War II Victory Medal; and the National Defense Service Medal.
Captain Yarbrough was a member of the Sigma Alpha Epsilon, Theta Kappa Psi, and Sigma Phi Omega fraternities; the American Medical Association; Association of Military Surgeons; the Army Medical Society and the Ancient Order of the Deep.
His father served as Lieutenant in the Medical Corps of the U . Navy in World War I, and was a physician and mayor of the city of Auburn, Alabama, during the period of 1906-1946. His brother, Lieutenant (jg) Byron C. Yarbrough, USNR, was killed at Iwo Jima in 1945.