William Leonard Williams (1829–1916) was an Anglican bishop of Waiapu. He was regarded as an eminent scholar of the Māori language. His father, William Williams, was the first Bishop of Waiapu, Williams was the third bishop, and his son, Herbert Williams, was the sixth bishop of Waiapu.

Māori, or te reo Māori, commonly shortened to te reo, is an Eastern Polynesian language and the language of the Māori people, the indigenous population of mainland New Zealand. A member of the Austronesian language family, it is related to Cook Islands Māori, Tuamotuan, and Tahitian. The Maori Language Act 1987 gave the language recognition as one of New Zealand's official languages. There are regional dialects. Prior to contact with Europeans, Māori lacked a written language or script. Written Māori now uses the Latin script, which was adopted and the spelling standardised by Northern Māori in collaboration with English Protestant clergy in the 19th century.