Alvar Palmgren (28 April 1880 – 30 November 1960) was a Finnish botanist and plant ecologist. Palmgren studied botany at the University of Helsinki under professor J.P. Norrlin. He graduated (Fil.kand.) in 1906 and obtained his Ph.D. in 1914. He became docent of botany at the University of Helsinki 1916 and professor of botany at the same university in 1928 (from 1938, the first in the special Swedish-language chair of botany). He retired in 1950.