William Battie (sometimes spelt Batty), 1 September 1703–13 June 1776, was an English physician who published in 1758 the first lengthy book on the treatment of mental illness, A Treatise on Madness, and by extending methods of treatment to the poor as well as the affluent, helped raise psychiatry to a respectable specialty.
He was President of the Royal College of Physicians in 1764.