Ryūhoku (竜北町; -machi) was a town located in Yatsushiro District, Kumamoto, Japan.
On October 1, 2005 Ryūhoku was merged with the town of Miyahara, also from Yatsushiro District, to form the new town Hikawa, as part of the "Great Heisei Merger" government initiative.
As of 2003, the town had an estimated population of 8,430 and a density of 360.26 persons per km². The total area was 23.40 km².
The town's output is mainly agricultural, with the major crops being nashi pears, strawberries, glutinous rice, and igusa straw for making tatami mats. Other minor crops include wheat, cabbages, tobacco, and various other vegetables and flowers. Cattle production is also increasing in popularity.
The hills in the east part of the town are home to several ancient Kofun tombs, of interest to archiologists studying that era.