George Fielding Bilyeu Sr., 56, a retired foreign service reserve officer and personnel official with the Agency for International Development, died of Cancer Saturday at Commonwealth Doctors Hospital in Fairfax.

Mr. Bilyeu began his career with the State Department in Tehran, Iran, in 1954. He was a personnel officer with AID in Washington from 1959 to 1962, then held a similar post in Saigon, Vietnam, for the next two years.

Later postings included that of executive officer of the AID missions in Seoul, Korea, and Kabul, Afghanistan. He returned to Vietnam in 1974 and was evacuated from that city a year later when it was taken by enemy forces.

His last post, from 1976 until retiring for reasons of health last August, was as deputy chief of foreign service personnel management.

He was a Scottish Rite Mason and life member of a lodge in Manila, the Philippines. In 1968, he helped found the MacArthur Masonic Lodge No. 183 in Seol, Korea.

Mr. Bilyeu was a native of Missouri and a 1950 graduate of Drury College in Springfield, Mo. He was an Army hospital corpsman during World War II. Before joining the State Department, he worked for the U.S. Army in Copenhagen, Denmark, as an administrative assistant.

He had lived in Falls Church and Arlington before moving to Fairfax in 1972.

Survivors include his wife, Roxanne, and three sons, Army 1st Lt. John M., George F. Jr., and Christian, all of Fairfax; another son, Army 1st Lt. David Md., of Fort Stewart, Ga.; three brothers, Halleck, of Harrisonville, Mo., Bobby, of Saugus, Calif., and Roger, of Hemet, Calif.; and three sisters, Opal, of Cleveland, Barbara Norris of Hemet, and Faye Shackleford of Saint Elizabeth, Mo.

The family suggests that expressions of sympathy be in the form of contributions to the Shriners Hospitals for Crippled Children, P.O. Box 25356, Tampa, Fla., 33623.