George Johnstone (1730 – 24 May 1787) was an officer of the Royal Navy who saw service during the War of the Austrian Succession, the Seven Years' War and the American War of Independence, rising to the rank of post-captain and serving for a time as commodore of a squadron. In a multifaceted career he was also a member of Parliament, a director of the East India Company, a member of the Carlisle Peace Commission and the first Governor of West Florida from 1763 until 1767.