The son of J.W. Johnson, a bank manager and circuit steward of Whitby, he was born on 5 April 1901 in Leeds, into a staunchly WM family. His sister was Myra Johnson and his brother Leslie W. Johnson, headmaster of Shebbear College. He graduated with first-class honours in Natural Science from Balliol College, Oxford, was involved in continuing research in spectroscopy and was considered in some quarters to be one of Britain's outstanding physicists. He lectured in Physics at Queen's University, Belfast 1923-1927 and at King's College, London, 1927-1934 before emigrating to Australia, where he was Master of Queen's College, University of Melbourne from 1934 to 1964. He had much in common with his close friend Leslie D. Weatherhead, including his liberal theology and approach to sexuality.
His appointment to Queen's College was controversial, being opposed by the evangelical wing of the Church. But under his leadership Queen's built up both teaching staff and student numbers and strengthened its ties with the University. In his retirement he fostered his interest in such esoteric subjects as mysticism, psychic research and theosophy. He was associated with the Santiniketan Park Association (named after a property he owned in the Dandenong Ranges outside Melbourne), popularly known as 'the Family', a body investigated by the police and subject to criminal charges.
He died in 1987.