Sir Christopher Hubert Llewellyn Smith FRS HonFInstP (born 19 November 1942) is an Emeritus Professor of Physics at the University of Oxford.

[9] After his DPhil he worked at the Lebedev Physical Institute in Moscow, CERN and then the SLAC National Accelerator Laboratory before returning to Oxford in 1974.

Llewellyn Smith was elected a Fellow of the Royal Society in 1984.

Until 2009 he was Director of UKAEA Culham Division, which holds the responsibility for the United Kingdom's fusion programme and operation of the Joint European Torus (JET).

[13] In 2013, he joined the National Institute of Science Education and Research (NISER), Bhubaneswar, India as a Distinguished Professor.