Wainui is a locality in the Rodney Ward of the Auckland Region of New Zealand.

The Wainui Stream flows south-west through the area and into the Kaukapakapa River.

[4] Wainui was settled by people from England, Scotland and Ireland around 1850, including the Hutson, Thick, King, Lloyd and Jacobs families.

[6] New Zealand explorer Charles Heaphy owned much of the land at Wainui, selling 104 acres (42 ha) to brickmaker William Lamont in 1862.

[6] In 1894, cartoonist Trevor Lloyd married Lamont's daughter Emily at the church.

During the 1960s the Waitemata County allowed for land to be subdivided into lifestyle blocks.

The results were 92.5% European (Pākehā); 9.4% Māori; 1.6% Pasifika; 4.1% Asian; 0.4% Middle Eastern, Latin American and African New Zealanders (MELAA); and 3.4% other, which includes people giving their ethnicity as "New Zealander".