Charles Oatley was born 14 February 1904, the son of William Oatley and Ada Mary Dorrington; he was educated at Bedford Modern School and St John’s College, Cambridge. In 1930 he married (Dorothy) Enid West; they had two sons.

After his graduation, Oatley spent two years as a research physicist, working for Radio Accessories Limited, making thermionic radio valves. After this firm collapsed in 1927, Oatley's former supervisor, Professor Edward Appleton, offered him a post in the Department of Physics at King's College London, first as Demonstrator, then later as a lecturer (1927-39), though he also continued to work as a consultant in the valve manufacturing industry, for Lissen Limited. During the war, Oatley worked on the development of radar at the Ministry of Supply Air Defence Research and Development Establishment, (1939-45), becoming Acting Superintendent in charge of scientific work, (1944-45). Back in peace-time Oatley came to Cambridge, first as Lecturer, later Reader, at the University Department of Engineering (1945-60), carrying out his early research into the Scanning Electron Microscope. He then became Professor of Electrical Engineering, (1960-71), while he was also a Fellow of Trinity College, Cambridge, from 1945. Outside his research work, Oatley was Director of the English Electric Valve Company, (1966-85). He was also a member of various institutions, including: Council, Institute of Electrical Engineers, 1954-56, 1961-64 (Chairman of the Radio Section, 1954-55); Council, Royal Society, (1970-72); Foreign Associate, National Academy of Engineering, United States, (1979).

Oatley's honours and awards include: Honorary Fellow, Royal Microscopical Society (1970); FKC (1976); Achievement Award, Worshipful Company of Scientific Instrument Makers, (1966); Duddell Medal, Institute of Physics and Physical Society (1969); Royal Medal, Royal Society (1969); Faraday Medal, IEE, (1970); Mullard Award, Royal Society, (1973); James Alfred Ewing Medal, ICE, (1981); Distinguished Scientist Award, Electron Microscopy Society of America, (1984); Howard N. Potts Medal, Franklin Institute, (1989). He was knighted in 1974; OBE 1956; MA; FRS 1969, FEng, FIEE, FIEEE. Oatley died on 11 March 1996.

Oatley's publications include: Wireless Receivers, (1932); The Scanning Electron Microscope, (1972); Electric and Magnetic Fields, (1976); papers in scientific and technical journals.