Henry St John-Mildmay may refer to: Sir Henry St John-Mildmay, 3rd Baronet (1764–1808), MP for Westbury, Hampshire and Winchester Sir Henry St John-Mildmay, 4th Baronet (1787–1848), MP for Winchester Sir Henry St John-Mildmay, 5th Baronet (1810–1902}, British Army officer See also St John-Mildmay Baronets