Otanmäki is a village to the south-west of Kajaani, Finland. Otanmäki is located in Vuolijoki within the bounds of the City of Kajaani municipality.
The railway rolling stock manufacturer Transtech Oy has a factory in Otanmäki, which has produced many of VR's railway carriages.
Coordinates: 64°06′35″N 27°06′20″E / 64.10972°N 27.10556°E