Hanamaki is located in central Iwate Prefecture, in the Kitakami River valley at the conflux of three rivers with the Kitakami River; the Sarugaishi-gawa from the east and the Se-gawa and Toyosawa-gawa from the west. In the west the city rises to the foothills of the Ōu Mountains with the highest peak being Mt. Matsukura at . To the east the city rises to the highest peak in the Kitakami Range, Mount Hayachine at . The largest reservoir is Lake Tase on the Sarugaishi River. Lake Hayachine on the Hienuki River is quite spectacular with steep mountains rising above it. Lake Toyosawa is in the western part of the city on the Toyosawa River. Parts of the city are within the borders of the Hayachine Quasi-National Park. A chain of 12 hot springs that lie along the edge of the Ōu Mountains form the Hanamaki Onsenkyo Village.