Niyodogawa (仁淀川町, Niyodogawa-chō) is a town located in Agawa District, Kōchi Prefecture, Japan.
The town was formed on August 1, 2005 from the merger of the town of Ikegawa, the village of Agawa, both from Agawa District, and the village of Niyodo, from Takaoka District.
As of May 1, 2017, the town has an estimated population of 5,676 and a density of 17 persons per km². The total area is 332.96 km².
The town is situated on the upper reaches of the Niyodo River. Routes 33 (the Tosa Kaidō), 439, and 494 link it with surrounding areas in Shikoku.