Merritt Lyndon Fernald (October 5, 1873 - September 22, 1950) was an American botanist. In his time he was regarded as the most respected scholar of the taxonomy and phytogeography of the vascular plant flora of temperate eastern North America. He published more than 850 scientific papers and wrote and edited the seventh and eighth editions of Gray's Manual of Botany. Fernald also wrote a book Edible Wild Plants of Eastern North America in 1919-1920 with Alfred Kinsey, published in 1943.
Fernald was born in Orono, Maine, his father was Merritt Caldwell Fernald, a college professor at the University of Maine, and his mother was Mary Lovejoy Heywood. He attended Orono High School, during high school he decided that he wanted to become a botanist, he collected plants around Orono and had two botanical papers published while still at high school. He attended Maine State College for a year, but at age 17 was invited to work as an assistant at the Gray Herbarium at Harvard University. He began studying at Harvard in 1891 and graduated in 1897, then he joined the faculty as a teacher and also remained working at the Herbarium.