William Frederick Windham

William Frederick Windham (9 August 1840 – 2 February 1866) was the son of William Howe Windham and the heir to Felbrigg Hall in the county of Norfolk, England. In 1861–62, he was the subject of a "lunacy" case after he married a woman of whom his uncle did not approve, causing his family to claim that he was incapable of managing his affairs. Windham won the case in a ruling that characterised him as eccentric rather than a lunatic.

The case was described in the British Journal of Psychiatry as "a significant event in psychiatric history" in the transition from "legal management in psychiatric illness and towards medical management".

A spendthrift, Windham frittered away his considerable fortune and, facing legal fees of £20,000 from the case, was forced to declare bankruptcy and sell Felbrigg Hall. He moved into a local hotel but continued his dissolute lifestyle and worked as a coach driver before dying at the age of 25.