is a train station in the town of Koumi, Minamisaku District, Nagano Prefecture, Japan, operated by East Japan Railway Company (JR East).
Koumi Station is served by the Koumi Line and is 48.3 kilometers from the terminus of the line at Kobuchizawa Station.
The station consists of one ground-level side platform and one island platform connected to the station building by a level crossing. The station has a Midori no Madoguchi staffed ticket office.
Koumi Station opened on 11 March 1919. With the privatization of Japanese National Railways (JNR) on 1 April 1987, the station came under the control of JR East.
In fiscal 2015, the station was used by an average of 199 passengers daily (boarding passengers only).