Otto Stapf FRS (23 April 1857, in near Bad Ischl – 3 August 1933, in Innsbruck) was an Austrian born botanist and taxonomist, the son of Joseph Stapf, who worked in the Hallstatt salt-mines. He grew up in Hallstatt and later published about the archaeological plant remains from the Late Bronze- and Iron Age mines that had been uncovered by his father. In the end, Stapf moved to Royal Botanic Gardens, Kew in 1890. He was keeper of the Herbarium from 1909 to 1920 and became British citizen in 1905. He was awarded the Linnean Medal in 1927.