The Thao/Ngan () are a small group of Taiwanese indigenous peoples who have lived near Sun Moon Lake (Lake Candidius) in central Taiwan for at least a century, and probably since the time of the Qing dynasty. The Thao/Ngan people numbered around 800, making them one of the smallest of all of the recognized indigenous peoples in Taiwan (a number of indigenous peoples, both smaller and larger than the Thao in population, remain unrecognized by the Taiwanese government).
Despite their small group size, the Thao/Ngan have retained their customs, beliefs and traditional culture and language until now, though they have been assimilated into mainstream culture as well. Most of the members of this ethnic group work in the tourism industry at Sun Moon Lake. The Chi-Chi earthquake of 1999 damaged or destroyed 80% of the houses of the Thao/Ngan.
The Thao/Ngan people have their own language, the Thao language, which is nearly extinct and spoken by only a few, mostly elders, of the (already small) Thao ethnic population. The language has been sinicized. Most people who speak Thao are bilingual or trilingual and can speak Mandarin Chinese and/or Taiwanese as well. The Thao/Ngan language is classified as a Northern Formosan language, which is a geographical subgroup of the much larger Austronesian language family. The Thao language has loanwords from the Bunun language, spoken by the Bunun ethnic group of which the Thao/Ngan cooperated with as well as intermarried.
According to Thao oral history, the Thao people originally live in Chiayi, later moved to Alishan Range, before eventually settling around Sun Mun Lake as well as Lalu Island in the middle of the lake. According to the legend, they saw a deer and wanted to eat it, so they chased it until they arrived in the side of Sun Moon lake. Then the deer ran into the water, leaving the Thao by themselves. They could only wait. The Thao people then slept at Sun Moon Lake. One of the elders dreamed of a fairy in a white cloak. He said to them "I am the deer that led you here.