The suburb is located on flat land at the southern end of the Ōtāhuhu isthmus, at the end of an arm of the Tamaki River and 18 kilometres southeast of Auckland city centre.

It is located on State Highway 1, and the North Island Main Trunk railway passes by the Middlemore Hospital.

The name 'Middlemore' refers to a region that was once known as Kohuora and was farmed beginning in the 1840s by William Thorne Buckland, who was joined by his younger brother, Alfred Buckland, in 1850. the Middlemore name came from a home that was originally owned by Richard Fairburn, the son of Anglican missionary William Thomas Fairburn, the house is now a part of the nearby Auckland Golf Club clubhouse.

[3] The suburb of Middlemore sits on the previous site of the Waokauri / Pūkaki portage, which allowed overland connections for canoes between the Waitematā and Manukau harbours.

The results were 41.3% European (Pākehā), 23.9% Māori, 26.1% Pasifika, 17.4% Asian, and 4.3% other, which includes people giving their ethnicity as "New Zealander".