Murdoch Mackenzie, FRS (1712–1797) was a hydrographer and cartographer.
Born in Orkney and employed by the Royal Navy, he became the first person to accurately chart the coastline around North Ronaldsay where many vessels had come to grief. His work led to the construction of a lighthouse at Dennis Head. North Ronaldsay and his charts are still in use by shipping today.
He also surveyed the north coast of Ireland and the west coast of Scotland, publishing the results in "Nautical description of the west coast of Great Britain from Bristol Channel to Cape Wrath" (1776) [1]
He was elected a Fellow of the Royal Society in 1774.
He died in Minehead, Somerset in 1797.