八幡平市（日语：八幡平市／はちまんたいし）是位于岩手县西北部的一市。设立于2005年（平成17年）9月1日，由岩手郡西根町、同郡松尾村、同郡安代町合并诞生。

Hachimantai(八幡平市,Hachimantai-shi) is a city located in Iwate Prefecture, Japan. As of February 2014, the city had an estimated population of 27,146 and a population density of 31.5 persons per km. The total area was 826.25  km.