Saku may refer to:
- Saku, Nagano, a city in Japan
- Saku, Nagano (Minamisaku), a town in Japan
- Saku Parish, a rural municipality in Harju County, Estonia
- Saku, a small borough in Saku Parish, Harju County, Estonia
- Saku Brewery, an Estonian brewery
- Saku (song), a song by the band Dir en grey
- Saku Constituency, an electoral constituency in Kenya
- Saku is also a Finnish male given name
- Saku Koivu, Finnish ice hockey player
- Saku Pesonen, Finnish footballer
- Saku Puhakainen, Finnish footballer