Erast Parmasto (October 28, 1928 – April 24, 2012) was a noted Estonian mycologist, bioscientist and botanist and onetime director of the Estonian Institute of Zoology and Botany.
Parmasto was born in Nõmme. He became a member of the Estonian Institute of Zoology and Botany in 1950 and served as its director from 1985 to 1990. His establishment of a mushroom herbarium in 1950 has since seen recognition of 160,000 samples, 37,000 of which Parmasto himself collected.
Parmasto published more than 150 papers and 200 articles during his academic career and his works are commonly used in popular scientific and academic journals in Estonia. His expertise in the field of mycology has resulted in him being nicknamed "Seenevana", or the "grand old man of mushrooms". As a mycologist, the field with which Parmasto was most associated, he was best known for his establishment and enhancement of databases for species of mushrooms within Estonia. He was also the author of the first Estonian-language textbook on biosystematics in history. He was furthermore one of the driving forces behind the establishment of Liiva-Putla Nature Reserve, one of only five areas created for the protection of mushrooms in Europe.