Martins Bay (Whakatipu Waitai or Te Remu) is an indentation in the southwest coast of New Zealand's South Island.

It lies immediately to the south of Big Bay and some 30 kilometres north of the mouth of Milford Sound at the northern tip of Fiordland.

In the early days of European settlement, it was planned to be the harbour for a town, Jamestown, located immediately inland on the shores of Lake McKerrow.

Jamestown was founded in 1870,[1][2] after James Hector claimed that a road could follow the route he took in 1863,[2] but the terrain, weather, and difficulty of getting supplies to the township caused the project to fail.

The ship that dropped off the first settlers foundered as it left the bay; their first baby born there was the daughter of passengers who intended to go on to Greymouth.