Waimakariri is a New Zealand parliamentary electorate, formed for the 1996 election and returning one Member of Parliament to the New Zealand House of Representatives. The MP for Waimakariri is Matthew Doocey of the National Party. He has held this position since the 2014 election and takes over from Kate Wilkinson, who defeated Clayton Cosgrove (Labour) in the 2011 election.
Waimakariri centres on metropolitan Christchurch and spreads northward up the coast of the South Island. From Christchurch it contains the suburbs of Casebrook and Belfast; from Waimakariri District to its north, it takes in the towns of Kaiapoi and Rangiora as well as a selection of small inland localities such as Cust and Oxford. Boundary changes following the 2006 census were relatively minor; Waimakariri managed to avoid the upheaval wrought upon electorates in Christchurch, losing Bishopdale to Ilam and the last remaining segment of Papanui to Christchurch Central.
Along with neighbouring Selwyn, Waimakariri has been experiencing strong population growth, with many people from Christchurch displaced by the earthquakes. In the 2013/14 boundary review by the Representation Commission, Waimakariri lost most of Redwood and Marshland to Christchurch Central and Christchurch East respectively, while it gained the less populated Harewood north of Sawyers Arms Road from Selwyn.