Olav Gjærevoll (24 September 1916 – 30 August 1994) was a Norwegianbotanist and politician for the Labour Party. Gjærevoll was a professor of botany at the University of Trondheim from 1958 to 1986, and was a specialist in alpine plants. Ín 1950 he issued the exsiccataM. Foslie: Lithothamnia selecta exsiccata distributing specimens collected by Mikael Heggelund Foslie.[1] In politics, he served as Minister of Social Affairs from February to August 1963 and again from September 1963 to October 1965; as the last Minister of Pay and Prices from 1971 to 1972 and as the first Minister of the Environment from May to October 1972. He also served as Mayor of Trondheim from 1958 to 1963 and again from 1980 to 1981.
As an elected politician he was elected to the Storting from Sør-Trøndelag in 1965. He had previously served in the position of deputy representative during the terms 1958–1961 and 1961–1965. On the local level he was a member of Trondheim city council from 1951 to 1963, 1967 to 1968 and 1979 to 1987, serving as mayor for two periods 1958–1963 and 1979–1981.