Haapakoski is a Finnish surname. Notable people with the surname include:
Aarne Haapakoski (1904–1961), Finnish pulp writer Antti Haapakoski (born 1971), Finnish hurdler Mikko Haapakoski (born 1967), Finnish ice hockey defender Niko Haapakoski (born 1996), Finnish volleyball player Paula Haapakoski (born 1977), Finnish orienteering competitor Tapani Haapakoski (born 1953), Finnish Olympic pole vaulter