Mataiva, Tepoetiriura or Lazarev atoll is a coral atoll in the Tuamotu Archipelago. It is located in the Palliser group, and is the westernmost of the Tuamotus. The nearest atoll, Tikehau, is located 35 km to the east. Rangiroa is located 79 km to the east, and Tahiti is 311 km to the south.

The Tuamotu Archipelago or the Tuamotu Islands are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extending over an area roughly the size of Western Europe. Their combined land area is 850 square kilometres. This archipelago's major islands are Anaa, Fakarava, Hao and Makemo.