Henry Thomas Marsh CBE FRCS (born 5 March 1950) is a leading British neurosurgeon, and a pioneer of neurosurgical advances in Ukraine. His widely acclaimed memoir Do No Harm: Stories of Life, Death and Brain Surgery was published by Orion Publishers in 2014 and according to The Economist is "So elegantly written it is little wonder some say that in Mr Marsh neurosurgery has found its Boswell."
Marsh attended the Dragon School in Oxford and Westminster School in London. Later he read Politics, Philosophy and Economics at University College, Oxford University, achieving First Class Honours, before graduating with Honours in Medicine from the Royal Free Medical School.
Marsh was until 2015 the senior consultant neurosurgeon at the Atkinson Morley Wing at St George's Hospital, south London, one of the country's largest specialist brain surgery units.
He specialises in operating on the brain under local anaesthetic and was the subject of a major BBC documentary Your Life in Their Hands in 2004, which won the Royal Television Society Gold Medal.