Maupihaa, Atoll in the Leeward Islands, French Polynesia

Maupihaa is an atoll in the Leeward Islands of the Society Islands, about 8 km long, with a lagoon up to 40 m deep. Its outer reef is continuous except for a small passage on the western side. The eastern side is a narrow, thickly vegetated islet, Motu Maupihaʻa, and smaller islets bring the land area to 2.6 km².

A German warship ran aground on the reef in 1917 and its crew built a settlement using materials salvaged from the wreck. This event shaped the atoll's early modern history and left marks on the landscape.

Maupihaʻa is listed as permanently uninhabited, though a village stands on Motu Maupihaʻa and seven people were counted there on 27 August 2023. The atoll's name survives in alternate forms including Mopelia, Maupelia and Cäcilieninsel, the name German sailors gave it in 1917. Coconut palms planted for copra cover the land.

The outer reef is continuous except for one small passage on the western side, so that gap is the only way into the lagoon. The atoll lies 72 km southeast of Manuaʻe, its nearest neighbour, and supply ships are rare; the most recent one called in 2021. There is no airstrip and no regular service.

The atoll is listed as permanently uninhabited, yet a sailing vessel named Russula arrived in August 2023 and its crew donated clothes, tools and motor oil for the outboard motors of the islanders. The most recent supply ship had called in 2021.