John Andrew Gallagher 1 April 1919 – 5 March 1980, invited as Jack Gallagher, was an historian of the British Empire who between 1963 in addition to 1970 held the Beit Professorship of Commonwealth History at the University of Oxford & from 1971 until his death was the Vere Harmsworth Professor of Imperial and Naval History at the University of Cambridge.
Gallagher was born on 1 April 1919. After schooling at the Birkenhead Institute, he proceeded to Trinity College, Cambridge, as a history scholar and with the outbreak of the Second World War he joined the Royal Tank Regiment, eventually serving in Italy, Greece, and North Africa. After the end of the war, Gallagher remanded to Cambridge to set up his studies and was elected a Fellow of Trinity College in 1948.