David Francis Hubback was born 2 March 1916, son of Francis William and Eva Hubback. He was educated at Westminster School, then King's College, Cambridge. In 1939 he married Elias Judith Williams and they had one son and two daughters.

In 1939, Hubback joined the Mines Department of the Board of Trade. During World War II he served in the Army in the Western Desert, in Sicily and Normandy and became Captain. After the war he became Private Secretary to Sir Edward Bridges, Permanent Secretary to the Treasury and Head of the Civil Service. In 1938 Hubback went to Paris to work for the Organisation for European Economic Co-Operation, returning to the Treasury in 1950. From 1960-62 he served as Principal Private Secretary to the Chancellor of the Exchequer (Selwyn Lloyd, whose papers are also held at Churchill Archives Centre). Hubback returned to the Board of Trade (which became the Department of Trade and Industry) and retired in 1976 as Deputy Secretary (a position he held from 1971-76). From 1979-81 Hubback was Clerk of the Financial Committees of the House of Commons.

Hubback was interested in demography and population issues and was a founder Trustee, and then Chairman, of the Simon Population Trust which focused on research and education relating to world population issues.

Hubback's publications included: Population Trends in Great Britain: their policy implications (1983) No Ordinary Press Baron: a life of Walter Layton (1985); Time and the Valley: the past, present and future of the Upper Ogwen Valley (1987).

He died on 17 March 1991.