Egil Morris Baardseth (born 2 May 1912 in Bærum, died on 29 January 1991 in Trondheim) was a Norwegian botanist and phycologist.
He attended the University of Oslo, and for his doctoral work, participated in the 1937-1938 Norwegian Scientific Expedition to Tristan da Cunha in the southern Atlantic Ocean.
Upon his return he successfully defended his dissertation and published The Marine Algae of Tristan da Cunha (1941), which includes an account of the 125 species of red, brown and green algae documented on the expedition.
As many as 49 species were endemic to Tristan da Cunha, for which he is credited as first describing.
In 1966-1967 he was UNESCO's representative in Cuba, initiating the exploration of algal resources, and from 1970 to 1980 he was professor of marine botany at the University of Bergen.