William Douglas (died 1791) was a Scottish ship captain and an oceanographer maritime fur trader during the late 18th century. He worked with the British trader and Captain John Meares, commanding the ship Iphigenia Nubiana. He was involved in the Nootka Crisis of 1789, which brought Britain and Spain to the brink of war. A few years later he was captain of the American ship Grace. In 1791 he partnered with Captain John Kendrick in an attempt to open trade with Japan.