John Propst Blane (July 15, 1929 – April 13, 2012) was an American diplomat.
He soon became vice consul in Mogadishu, Somalia, in 1957, in Asmara, Eritrea, from 1958 to 1960), and in Salzburg, Austria, from 1960 to 1962).
He returned to the State Department as a country officer for Togo, Dahomey (now Benin), Chad, and Gabon from 1966 to 1968.
Blane was Deputy Chief of Mission in Fort Lamy (now N'Djamena), Chad, from 1969 to 1972.
He was the Director of Bilateral Programs Division of the Office of International Activities at the Environmental Protection Agency from 1975 to 1977.
From 1980 to 1981, Blane was a member of the executive seminar in national and international affairs at the Foreign Service Institute.