Walter Langdon-Brown

Sir Walter Langdon-Brown (1870–1946) was a British medical doctor.

He was born in Bedford, the son of the Rev. John Brown of Bunyan's Chapel, Bedford and his wife, Ada Haydon Ford (1837–1929). His mother was a niece of John Langdon Down, describer of Down syndrome. His sister was Florence Ada Keynes, the social reformer, wife of John Neville Keynes and mother of John Maynard Keynes (see Keynes family).

He was educated at Bedford School and St. John's College, Cambridge. He served as an army doctor in the Second Boer War and World War I. He worked at St Bartholomew's Hospital with Samuel Gee, and later at the Metropolitan Free Hospital, London.

He was the author of a number of medical textbooks, a lecturer at the Royal College of Physicians, and went on to become Regius Professor of Physic at the University of Cambridge. He was knighted on his retirement in 1935.

The Langdon-Brown lectureship at the Royal College of Physicians was founded in his memory in 1950 by a gift from his second wife, Lady Freda Langdon-Brown.