Iwate 4th district was a constituency of the House of Representatives in the Diet of Japan (national legislature). It was located in southwestern Iwate and consisted of the cities of Hanamaki, Kitakami and Ōshū as well as the Waga and Isawa Districts. As of 2012, 305,917 eligible voters were registered in the district. The only representative for Iwate 4th district from its creation in 1996 to its abolition has been former Liberal Democratic Party secretary-general Ichirō Ozawa (LDP→JRP→NFP→LP→DPJ→LF→TPJ→PLP).