Since the 1969 election, the number of electorates in the South Island was fixed at 25, with continued faster population growth in the North Island leading to an increase in the number of general electorates. There were 84 electorates for the 1969 election, and the 1972 electoral redistribution saw three additional general seats created for the North Island, bringing the total number of electorates to 87. Together with increased urbanisation in Christchurch and Nelson, the changes proved very disruptive to existing electorates.  In the South Island, three electorates were abolished, and three electorates were newly created. In the North Island, five electorates were abolished, two electorates were recreated, and six electorates were newly created (including King Country).
The King Country electorate was formed from area that previously belonged to the Waimarino and Waitomo electorates, which were both abolished. The King Country electorate covered a largely rural area with a dispersed population. It has no cities. The largest towns are Otorohanga and Te Kuiti.
The previous representative of the Waimarino electorate was Roy Jack who transferred to the enlarged Rangitikei electorate in 1972.David Seath had held the Waitomo electorate since 1954 and he retired in 1972. This gave Jim Bolger the opportunity to stand in the new King Country electorate when it was formed in 1972, and the area being a traditional stronghold for National, he won the election with ease. Bolger became Prime Minister in 1990 while representing the King Country electorate.
Wilson, James Oakley [First ed. published 1913] (1985). New Zealand Parliamentary Record, 1840–1984, 4th, Wellington: V.R. Ward, Govt. Printer, 266. OCLC154283103.
Norton, Clifford (1988). New Zealand Parliamentary Election Results 1946–1987: Occasional Publications No 1, Department of Political Science. Wellington: Victoria University of Wellington. ISBN 0-475-11200-8.