The original King Country Rugby Union was formed in 1905 by the Manunui, Matapuna, Oio and Kakahi rugby clubs. In 1907, the newly formed Taumarunui rugby club replaced Oio. The current King Country Rugby Football Union was formed in 1922, by the amalgamation of the first King Country Rugby Union (which was renamed as the Taumarunui Sub-union in 1922) along with the Ruapehu Sub-union in Ohakune (founded 1908), Maniapoto Sub-union in Te Kuiti (1907) and Ohura Valley Sub-union (1920). These were joined by Otorohanga Sub-union in 1927, Kawhia in 1926 and Kaitieke in 1933 with the Taupo Sub-union transferring from the Hawkes Bay Rugby Union in 1987. The Ruapehu Sub-union returned to its original parent union the Wanganui Rugby Union in 1970.