František Běhounek (Czech pronunciation: [ˈfrancɪʃɛk ˈbjɛɦounɛk]; 27 October 1898 Prague – 1 January 1973 Karlovy Vary) was a Czech scientist (radiologist), explorer and writer. The asteroid 3278 Běhounek is named after him.
Běhounek studied physics and mathematics at Charles University, later radiology in France with Marie Curie-Skłodowska. In 1920s, he was one of the founders of State Radiological Institute. In 1926, he took part in an expedition of Roald Amundsen to the North Pole with airship Norge. In 1928, as an expert on cosmic rays, he was a member of crew of airship Italia led by Umberto Nobile. He survived its crash in 1928, and later described it in book Trosečníci na kře ledové.
As a scientist, he worked in industrial companies, medical institutions, universities and in the state academy. Since the 1950s, he has participated in work of UNESCO.
Běhounek published about 28 novels (most of them aimed at young people, popularizing science or science fiction) and many scientific works.