Finn Adolf Erik Johan Malmgren (1895 – June 1928) was a Swedish meteorologist and Arctic explorer.
Malmgren studied in Göteborg, Sundsvall and Stockholm. In 1912 he started to study at the Uppsala University where he received a bachelor's degree in 1916. In 1917 Malmgren became assistant to professor Axel Hamberg in his observatory at Pårtetjåkko; in 1920 he returned to the meteorological institute in Uppsala and a year later was appointed assistant professor at Otto Pettersson's hydrographic institute for oceanic studies on an island in the Gullmarsfjord.
During 1922–25, Malmgren participated in the expedition of Roald Amundsen and Harald Ulrik Sverdrup in the Arctic, on board the Maud. In 1926 he was on board the Italian airship Norge which overflew the North Pole, where he used scientific instruments from František Běhounek.
In early 1927 he was decorated as a Commander of the Order of St. Olav.
In 1928 the scientist joined the expedition of Umberto Nobile with the airship Italia. During the third flight, on 25 May, the airship crashed and several members of the expedition were stranded on floating ice, Malmgren with an injured shoulder among them. On 30 May Malmgren, together with Italian officers Filippo Zappi and Adalberto Mariano, decided to walk back to Kings Bay for help. On 15/16 June Malmgren collapsed and asked to be left behind. On 11 July the Soviet pilot Boris Chukhnovsky, from the icebreaker Krasin, sighted Mariano and Zappi and also Malmgren's body. Mariano and Zappi were rescued the next day; the body of Finn Malmgren was not found.
The circumstances of Malmgren's death remain unclear. In the press Zappi and Mariano were suspected of abandoning Malmgren and even of cannibalising him.