Maarten Gerritsz Vries, or Fries, also referred to as de Vries, (18 February 1589, Harlingen - late 1647, at sea near Manila) was a 17th-century Dutch cartographer and explorer, the first Western European to leave an account of his visit to the Sea of Okhotsk and the island of Sakhalin.
Not much is known about the life of de Vries. He was probably born in Harlingen, Netherlands, in 1589 and spent many years in Taiwan. He is best remembered for his 1643 expedition to the north-western Pacific Ocean to discover the coast of Tartaria, on account of Anthony van Diemen, the governor in Batavia. This was the second expedition to look for legendary gold and silver islands in the Pacific, which nobody had discovered, after a failed expedition in 1639 under command of Matthijs Quast.