Sir David Ferrier FRS (13 January 1843 – 19 March 1928) was a pioneering Scottish neurologist and psychologist. Ferrier was born in Woodside, Aberdeen and educated at Aberdeen Grammar School before studying for an MA at Aberdeen University (graduated 1863). As a medical student, he began to work as a scientific assistant to the influential free-thinking philosopher and psychologist Alexander Bain (1818–1903), one of the founders of associative psychology. Around 1860, psychology was finding its scientific foundation mainly in Germany, with the rigorous research of Hermann von Helmholtz (1821–1894), who had trained as a physicist, and of Wilhelm Wundt (1832–1920). They focused their work mainly in the area of sensory psychophysiology, because it was the most rewarding for the approach based on the paradigms of experimental physics. Both worked at the University of Heidelberg. In 1864 Bain prompted Ferrier to spend some time in their laboratories.
On returning to Scotland, Ferrier graduated in medicine in 1868 at the University of Edinburgh. A few years later, in 1870, he moved in to London and started work as a neuropathologist at the King's College Hospital and at the National Hospital for Paralysis and Epilepsy, Queen Square. The latter - now the National Hospital for Neurology and Neurosurgery - was the first hospital in England to be dedicated to the treatment of neurological diseases and has a David Ferrier ward named in his memory.