John Iball was born in Hasland, Derbyshire. He attended University College, Bangor from where he graduated with a first class degree in physics in 1928.
After a year doing a teaching diploma, he took an MSc in 1930 and a PhD in 1932 in the study of crystal structures by X-ray. Iball then went to the Royal Institution in London where he worked under Sir William Bragg focusing on X-ray studies of organic compounds. This led him to study the molecular structure of cancer producing aromatic compounds and to an interest in carcinogenicity.
He joined the research staff of the Royal Cancer Hospital in London in 1934 and his contribution was recognised by the award of a DSc (Wales) in 1939. The following year Iball joined the team working on rocket science for the Ministry of Supply then, after the war, moved to Port Sunlight to work for Unilever.
In 1948 he was appointed a fellow at University College, Dundee where he was to remain until he retired. He lectured in the physics and chemistry departments and in 1969 was appointed Senior Gibb Fellow of the British Empire Cancer Campaign.
Iball was keen to share his enthusiasm for science with people outside the academic community. He formed the Tayside and Fife Branch of the British Association and was always willing to help local industries with scientific problems. After he retired in 1974 he continued to be active in these areas and to publish the results of his ongoing research. Iball died in Dundee.