The Upper Waitematā Harbour is an estuary of the Waitematā Harbour in the Auckland Region of New Zealand. It flows south-east from the town of Riverhead, and was historically the border between Waitakere City and North Shore City in Auckland.

Waitematā Harbour is the main access by sea to Auckland, New Zealand. For this reason it is often referred to as Auckland Harbour, despite the fact that it is one of two harbours adjoining the city. The harbour forms the northern and eastern coasts of the Auckland isthmus and is crossed by the Auckland Harbour Bridge. It is matched on the southern side of the city by the shallower waters of the Manukau Harbour.