Martti Henrikki Haavio (22 January 1899, Temmes – 4 February 1973, Helsinki) was a Finnish poet, folklorist and mythologist, writing poetry under the pen nameP. Mustapää. He was born on 22 January 1899 in Temmes, and died 4 February 1973. He was also a professor of folklore and an influential researcher of Finnish mythology. In 1960, Haavio married Aale Tynni, after his first wife died in 1951 of cancer. During Haavio's early career, he was a member of the Tulenkantajat literature club.
Bjarmien vallan kukoistus ja tuho: Historiaa ja runoutta. Porvoo Helsinki: WSOY, 1965.
Suomalainen mytologia. Porvoo Helsinki: WSOY, 1967.
Esseitä kansanrunoudesta. Articles published 1959 in Essais folkloriques par Martti Haavio. Studia Fennica 8. Suomalaisen Kirjallisuuden Seuran toimituksia 564. Helsinki: Suomalaisen Kirjallisuuden Seura, 1992. ISBN 951-717-703-8.