Alexander C. Johnpoll, 64, a Foreign Service officer for 26 years before retiring for health reasons in 1973, died of cancer Friday at Suburban Hospital in Bethesda. He was a resident of Chevy Chase.

Mr. Johnpoll joined the State Department in 1947. He was vice consul in Sydney for two years before serving as a political officer at the U.S. Embassy in Yugoslavia from 1949 to 1951. He was a political officer in Vienna from 1952 to 1957.

He was stationed in Washington from 1957 to 1961 and again from 1966 to 1969. He was deputy chief of mission in Somalia during the 1960s. His last post was as consul general in Hamburg from 1969 to 1973.

Mr. Johnpoll was a native of New York City. He was a graduate of the Juilliard School in New York City, the University of New Mexico and the National War College. He served with the Army in Europe during World War II.

He was a member of the Cosmos Club and the Kenwood Golf & Country Club.

His wife, Gudtney Karen Johnpoll, died in 1975. His survivors include his mother, Ray Johnpoll of New York City, and a brother, Dr. Bernard K. Johnpoll of Albany, N.Y.