There were two by-elections for the Tengatangi-Areora-Ngatiarua constituency in 2019:

March 2019 Tengatangi-Areora-Ngatiarua by-election, caused by the defection of Te-Hani Brown from the Democratic Party. November 2019 Tengatangi-Areora-Ngatiarua by-election, caused by the resignation of Te-Hani Brown.