Sir Victor Alexander Haden Horsley FRS FRCS (14 April 1857 – 16 July 1916) was a British scientist and professor. He was born in Kensington, London. Educated at Cranbrook School, Kent, he studied medicine at University College London and in Berlin, Germany (1881) and, in the same year, started his career as a house surgeon and registrar at the University College Hospital. From 1884 to 1890, Horsley was Professor-Superintendent of the Brown Institute. In 1886, he was appointed as Assistant Professor of Surgery at the National Hospital for Paralysis and Epilepsy, and as a Professor of Pathology (1887–1896) and Professor of Clinical Surgery (1899–1902) at University College London. He was a supporter of women's suffrage and was an opponent of tobacco and alcohol.