The Lord of Mann is the lord proprietor and head of state of the Isle of Man, currently King Charles III. Before 1504 the title was King of Mann.

The Isle of Man or Mann, is a self-governing British Crown Dependency in the Irish Sea, between Great Britain and Ireland. It is recognized as one of the Celtic nations, and is the homeland of the Manx people, a Celtic ethnic group. As head of state, Charles III holds the title Lord of Mann and is represented by a Lieutenant Governor. The government of the United Kingdom is responsible for the isle's military defence and represents it abroad.