Tahitian (Reo Mā`ohi or Reo Tahiti in Tahitian) is an indigenous language spoken mainly in the Society Islands in French Polynesia. It is an Eastern Polynesian language closely related to the other indigenous languages spoken in French Polynesia: Marquesan, Tuamotuan, Mangarevan, and Austral Islands languages. It is also related to the Rarotongan, New Zealand Māori, and Hawaiian languages.

Tahitian was first transcribed from the oral spoken language into writing by missionaries of the London Missionary Society in the early 19th century.

In French Polynesia, it is the most prominent of the indigenous Polynesian languages (reo mā’ohi) which also include;

When Europeans first arrived in Tahiti at the end of the 18th century, there was no writing system and Tahitian was only a spoken language. In 1797, Protestant missionaries arrived in Tahiti on a British ship called the Duff, captained by James Wilson. Among the missionaries was Henry Nott (1774–1844) who learned the Tahitian language and worked with Pomare II, a Tahitian king, to translate the English Bible into Tahitian. A system of 5 vowels and 9 consonants was adopted for the Tahitian Bible which would become the key text by which many Polynesians would learn to read and write.