Mount Underwood is part of the Darran Mountains and it is situated six kilometres east of Milford Sound in the Southland Region of the South Island.

It is set within Fiordland National Park which is part of the Te Wahipounamu UNESCO World Heritage Site.

Topographic relief is significant as the summit rises 2,120 metres (6,955 feet) above the Tūtoko Valley in two kilometres.

[2] The mountain's toponym honours Thomas Underwood, captain of the ship Rotomahana, which operated cruises in Fiordland.

The months of December through February offer the most favourable weather for viewing or climbing this peak.