Aotearoa (Māori: [aɔˈtɛaɾɔa], commonly mispronounced ⁱ/aʊtɪəˈroʊ.ə/ by English speakers) is the most widely known and accepted Māori name for New Zealand. It is used by both Māori and non-Māori, and is becoming increasingly widespread in the bilingual names of national organisations, such as the National Library of New Zealand / Te Puna Mātauranga o Aotearoa.

The original derivation of Aotearoa is not known for certain. The word can be broken up as: ao = cloud, dawn, daytime or world, tea = white, clear or bright and roa = long. It can also be broken up as Aotea = the name of one of the migratory waka that traveled to New Zealand, or the great Magellenic Cloud and roa = long. The common translation is "the land of the long white cloud". Alternative translations are ‘long bright world’ or ‘land of abiding day’ referring to the length and quality of the New Zealand daylight (when compared to the shorter days found further north in Polynesia) .

In some traditional stories, Aotearoa was the name of the canoe of the explorer Kupe, and he named the land after it. Kupe's wife (in some versions, his daughter) was watching the horizon and called "He ao! He ao!" ("a cloud! a cloud!"). Other versions say the canoe was guided by a long white cloud in the course of the day and by a long bright cloud at night. On arrival, the sign of land to Kupe’s crew was the long cloud hanging over it. The cloud caught Kupe’s attention and he said “Surely is a point of land”. Because of the cloud which greeted them, Kupe named the land Aotearoa. Aotearoa can also be broken up as: aotea-roa. Aotea is the name of one of the Māori migration canoes. The first land sighted was accordingly named Aotea (Cloud), now Great Barrier Island. When a much larger landmass was found beyond Aotea, it was called Aotea-roa (Long Aotea).