The Suigun Line (水郡線, Suigun-sen) is a Japanese railway line operated by East Japan Railway Company (JR East), which connects Mito Station in Ibaraki Prefecture and Asaka-Nagamori Station in Fukushima Prefecture, Japan.

The 15 banks owed money formed the Mito Railway Co. to acquire the line and continue its operation.

On 13 October 2019 as a result of heavy rainfall from Typhoon Hagibis, a bridge over the Kuji River was destroyed.

JR East announced that the bridge repairs would take until November 2020 at the earliest, but the section did not reopen until 27 March 2021.

Only 13 trains per day run the entire length of the line; most services are from Mito to Hitachi-Ōmiya, to Hitachi-Daigo, and to Hitachi-Ōta.