David Skae (1814–1873) was a Scottish physician who specialised in psychological medicine.
David Skae was born in Edinburgh on 5 July 1814. His parents were David Skae, an architect and builder, and Helen Lothian.  Both parents died when David was a child, and he was educated by his maternal uncle, the Rev. William Lothian, at St Andrews. At the age of fourteen Skae began his university career, studying liberal arts at the University of St Andrews. At sixteen years of age he left St Andrews to take up a post as a clerk in a lawyer's office in Edinburgh. Shortly thereafter he enrolled as a medical student and in 1835 he was awarded a medical licence from the College of Surgeons, Edinburgh. In the following year he was granted Fellowship of the College. In 1836 he began to teach in the extramural medical school, and his lectures on medical jurisprudence soon became popular. After delivering fourteen courses of lectures, he began the teaching of anatomy, having as colleagues James Young Simpson, Professor Spence, and William Fergusson. In 1842, St Andrews University awarded him a Doctorate of Medicine.
Meanwhile from 1836 Skae filled the office of surgeon to the Lock Hospital, and wrote several original papers on syphilis. He made insanity his special study, approaching it from the point of view of a student of nervous and mental physiology. In 1846 he obtained the appointment of physician superintendent of the Royal Edinburgh Asylum at Morningside, and held the post till his death, twenty-seven years later. During his tenure of office the institution doubled in size, and he attracted a succession of gifted assistant physicians. In 1873 he was nominated Morisonian lecturer on insanity at the Royal College of Physicians, Edinburgh; but he did not live to complete his term of office. He died at his official residence at Morningside, of oesophegeal cancer, on 18 April of that year. He had married Sarah, daughter of Major Macpherson of Ayr, and left issue.
Skae published papers on 'The Treatment of Dipsomaniacs' in 1858, and on 'The Legal Relations of Insanity' (1861 and 1867). His major work was the 'Classification of the Various Forms of Insanity on a Rational and Practical Basis.' He made this topic the subject of an address which he delivered at the Royal College of Physicians, London, on the occasion of his occupying the presidential chair of the Association of Medical Officers of Asylums (9 July 1863); and he further developed it in the Morisonian lectures on insanity, 1873. These lectures were completed and published posthumously by his pupil and successor, Dr. Thomas Smith Clouston. Skae's classification is founded upon what he called the 'Natural History of Insanity.' Instead of separating the insane into groups of maniacs, melancholiacs, and so on, Skae proposed that classification should be based on the underlying bodily condition of the patient—puerperal mania, traumatic mania, and so on. Skae's classification was not generally adopted. His definition of insanity was "a disease of the brain affecting the mind".
- Beveridge, Allan (2004). "David Skae (1814-1873)". Oxford Dictionary of National Biography. doi:10.1093/ref:odnb/25654.
- Urquhart, Alexander Reid (1897). "Skae, David". In Lee, Sidney. Dictionary of National Biography 52. London: Smith, Elder & Co. "sources: [Skae's papers in medical periodicals; Scotsman, April 1873; Journal of Mental Science for July 1873; personal knowledge.]"