The Ngauranga Gorge is in the Wellington Region of New Zealand. State Highway 1 runs through the gorge, a vital link between Wellington City and the Kapiti Coast and the main route north out of Wellington. It is 2 kilometres long and has a grade of approximately 8%. 65,000 vehicles a day travel through it, and it connects the Wellington Urban Motorway with the Johnsonville–Porirua Motorway. The road up the gorge was upgraded in 1940 as the Centennial Highway.
The Newlands Interchange, at the top of the gorge, was constructed in 1997/1998 to replace a simple junction, which caused a large amount of congestion.
The North Island Main Trunk Railway crosses the bottom of the gorge via an overbridge between the Tawa No 1 and Tawa No 2 Tunnels of the Tawa Flat deviation.
There is an industrial area with some retail outlets at the bottom of the gorge, where there was previously an abattoir. There are an abattoir and quarry part way up the gorge.
The name is derived from the former Nga Hauranga Maori settlement at the foot of the gorge.
The two kilometre cycle up the gorge is a daily mini-endurance test for many cycle commuters at the end of their working day. However the steep downhill for undertaken by cycle commuters in the mornings represents a relatively dangerous and thrilling start to their day. Cyclists regularly exceed 90 kilometers per hour while vehicular traffic tends to remain around 80 kilometers per hour due to the presence of a speed camera situated part way down the gorge which is set at 80 km/h.