Born in Troon, Ayrshire, McFadzean was educated locally then studied at the University of Glasgow (graduating MA) and the London School of Economics.

After working as a civil servant, he fought with the Duke of Cornwall's Light Infantry during World War II, reaching the rank of colonel[1] and seeing service in Egypt.

From 1964 to 1976, McFadzean served as the Managing Director of Royal Dutch Shell.

In 1976, he was appointed Chairman of British Airways by Harold Wilson.

[1] McFadzean was created a Knight Bachelor by Queen Elizabeth II in 1975.