He was educated at The Downs School near Malvern, Gresham's School, and Trinity College, Cambridge. In 1930, he was the winner of a bronze medal in the Public Schools Essay Competition organised by the Royal Society for the Protection of Birds.
He began research on the mechanism of nerve conduction, a field in which a strong tradition had been built up at Cambridge by Keith Lucas, A. V. Hill, and Lord Adrian. Within a year he had obtained clear evidence that the "local circuit" mechanism did explain the spread of activity from each point to the next as an impulse travels along a nerve fiber. For this work he was elected to a fellowship of Trinity College in 1936.
Hodgkin's first work was carried out on whole nerve trunks dissected from frogs, the classical material for investigations on nerve conduction. All his subsequent work on nerve tissue was done on isolated single fibers. By World War II he had published important papers on "subthreshold" potentials, that is, the electric events that lead up to the full-size nerve impulse, and on the electrical resistance of the protoplasm and surface membrane of the giant nerve fiber. He also issued, jointly with A. F. Huxley, a preliminary note on recording with an electrode actually inside a squid giant nerve fiber.
Hodgkin spent most of the war years developing airborne radar. He returned to Cambridge in 1945, holding college and university teaching appointments. From 1952 to 1969 he was a research professor of the Royal Society, and from 1970 a newly founded university professor of biophysics. He worked during this period at the Physiological Laboratory of Cambridge, as well as the Marine Biological Association at Plymouth in the autumn, when squid were available.
Alan Hodgkin died in 1998 at Cambridge.
From 1952 to 1969 he was a research professor of the Royal Society, and from 1970 a newly founded university professor of biophysics.
From 1970 to 1975 he was President of the Royal Society.
He was also elected to the American Association for the Advancement of Science, American Philosophical Society, American Academy of Arts and Sciences, Royal Danish Academy of Sciences and Letters, Deutsche Akademie, and Indian National Science Academy.
Alan Hodgkin married Marion Rous in 1944, whom he met while at Rockefeller Institute in 1938. She was the daughter of an American pathologist, Francis Peyton Rous, who won the 1966 Nobel Prize in Physiology or Medicine. She became Children's Book Editor at Macmillan Publishing Company and a successful writer of children's literature, including Young Winter's Tales and Dead Indeed. They had three daughters, Sarah, Deborah, and Rachel, and a son Jonathan. Jonathan Hodgkin became a molecular biologist at Cambridge University. Deborah Hodgkin is also a successful psychologist.
Thomas Hodgkin (1798-1866), who diagnosed Hodgkin's Lymphoma, was Alan Hodgkin's ancestor.