The Waitakere Tramline is a 2.5 kilometres (1.6 mi) long industrial narrow gauge railway near Swanson in the Waitākere Ranges south-west of Auckland in New Zealand, which is being used since 1907 for building and maintaining the dam and water pipeline at the Upper Nihotupu Reservoir.

It was used until 2014 also by the Waitakere Tramline Society Inc. for tourist excursions, which have been indefinitely ceased due to a risk assessment.

[1] The track with an original gauge of 2 ft 6 in (762 mm), which has later been regauged to 2 ft (610 mm) started originally at Swanson railway station and ran to a point above the Filter Station.

The lower section of the rail track from Swanson up beyond the Filter Station was lifted c. 1927.

[1] In November 2011, a leak in the adjacent 600mm diameter main water pipe triggered a substantial slip, taking out a 15m long section of the tramline with 6m of track left dangling in the air.