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