Te Whanganui / Port Underwood is a sheltered harbour which forms the north-east extension of Te Koko-o-Kupe / Cloudy Bay at the northeast of New Zealand's South Island, on the east coast of the Marlborough Sounds.

[1] There is evidence of a large Māori population at various times prior to European arrival in New Zealand.

In the 1820s the local Rangitane were defeated by the Ngāti Toa chief Te Rauparaha.

[3] On 16 June HMS Herald arrived with Major Thomas Banbury on board bringing the Treaty of Waitangi for the South Island chiefs to sign.

[5] The name of the harbour was officially altered to Te Whanganui / Port Underwood in August 2014.