Marcus E. Jones (April 25, 1852 – June 3, 1934) was an American geologist, mining engineer and botanist. Throughout his career he was known for being an educator, scientist and minister. As an early explorer of the western United States, he is known as the authority for numerous vascular plants. Much of his career was spent self-employed in Salt Lake City, Utah. In his later years, and after the death of his wife, he resided in Claremont, California.