Born at Banbury near Oxford, Hodgkin graduated from Cambridge University and became a fellow in 1936. He spent World War II working on radar for the Air Ministry. He then worked at the physiological laboratory at Cambridge, where he served as Foulerton Research Professor from 1952 to 1969 and as professor of biophysics from 1970 until 1981. He also served from 1978 to 1984 as master of Trinity College, Cambridge; he was knighted in 1972.

In 1951, with Andrew Huxley and Bernard Katz, he worked out the sodium theory to explain the difference in action and resting potentials in nerve fibers. Using the single nerve fiber (giant axon) of a squid, they were able to demonstrate that there is an exchange of sodium and potassium ions between the cell and its surroundings during a nervous impulse, which enables the nerve fiber to carry a further impulse. Hodgkin also showed that the nerve fiber's potential for electrical conduction was greater during the actual passage of an impulse than when the fiber is resting. For their work on the ‘sodium pump’ mechanism and the chemical basis of nerve transmission Hodgkin, Huxley, and John Eccles shared the Nobel Prize for physiology or medicine in 1963. He is the author of Conduction of the Nervous Impulse (1964). In 1992 he published his autobiography Chance and Design: Reminiscences of Science in Peace and War.