William Ross Yankey was born in Springfield, Kentucky, on 2 February 1913, son of John Sweeney and Frances (Ross) Yankey. He attended the University of Kentucky at Louisville, from which he received the degree of Bachelor of Science in mechanical engineering in 1936. He was associated with his brother as a Contracting Engineer in the Philippines in 1934 and from 1936 to 1940. He was commissioned an Ensign in the Civil Engineer Corps of the US Naval Reserve on 15 December 1939, and subsequently advanced in rank attaining that of Commander, to date from 1 December 1950, having transferred to the Regular Navy on 15 July 1946.
Upon receiving his commission in 1939, he was an inactive Reserve Officer until September 1940 when he was called to active duty and assigned to the Public Works Department in the Sixteenth Naval District with headquarters in Cavite, Philippine Islands. He was captured when the Japanese invaded the Philippines and was a Prisoner of War from January 1942 until February 1945. Upon his release from prison camp in 1945, he reported on board the flagship of the Command Service Force, SEVENTH Fleet (the USS San Clemente) in Leyte Gulf. It was determined from the then current register, while reopening his pay accounts, that he was the senior Ensign in the Navy. After a period of leave and rehabilitation, he had instruction from July to October 1945 at the Civil Engineer Corps Officer School, Davisville, Rhode Island.
He was Assistant Public Works Officer at the Naval Station, Key West, Florida until January 1948, after which he served as Officer in Charge of the Naval Industrial Reserve Plant, Kansas City, Missouri. He remained there until April 1949, when he joined the staff of the Commander Service Force, US Atlantic Fleet for duty as Assistant Staff Civil Engineer and later Staff Civil Engineer.
Between October 1951 and August 1954 he was Chief Staff Officer to the Commander Construction Battalions, Atlantic Fleet, after which he was assigned as Assistant Public Officer at the San Francisco (California) Naval Shipyard. In August 1955 he reported as Resident Officer in Charge of Construction in the San Francisco area and a year later became Officer in Charge of Construction, Subic Bay and Resident Officer in Charge of Construction, Manila, Philippine Island.
Commander Yankey had the Presidential Unit Citation Ribbon, the Presidential Unit Citation Ribbon awarded by the Republic of the Philippine Islands; the American Defense Service Medal, Base Clasp; the Asiatic-Pacific Campaign medal; the National Defense Service Medal; the Philippine Defense Ribbon; the Philippine Liberation Ribbon and the Philippine Independence Ribbon.
Commander Yankey was a member of the US Naval Institute, the American Society of Military Engineers and the Army-Navy Club, Manila, Philippine Islands.