Stephen Smith began his research career at the University of Minnesota and subsequently worked for the Ford Motor Company in the USA and in the Clarendon Laboratory, Oxford, before coming to Essex in 1973. He has worked on electron spin resonance, neutron scattering and light scattering in solids, and was involved for some time on work on the Jahn-Teller effect with a visiting position at Queen's University, Kingston, Ontario. He has also been a consultant on the plasma diagnostics programme at the Joint European Torus (JET) Laboratories. He was Head of Department 1991-94.
Outside the Physics Department, Stephen Smith spends much of his time in musical activities. He sings in the University of Essex Choir, is conductor and accompanist to a local choral society, and has give many organ recitals, including some in Germany and the USA.