Eric John Hewitt FRS (27 February 1919–31 December 2001) was a British plant physiologist. He was educated at Whitgift School, graduated with a first-class BSc in botany and chemistry from King's College London, and completed his PhD at the University of Bristol in 1948. He was a Reader in Plant Physiology at the University of Bristol from 1967 to 1984. He was made a Fellow of the Royal Society in 1982.