Koiwai Station (小岩井駅, Koiwai-eki?) is a train station in Takizawa, Iwate Prefecture, Japan.
Morioka - Ōkama - Koiwai - Shizukuishi - Harukiba - Akabuchi - Tazawako - Sashimaki - Jindai - Shōden - Kakunodate - Uguisuno - Ugo-Nagano - Yariminai - Ugo-Yotsuya - Kita-Ōmagari - Ōmagari