The Reverend Lancelot Edward Threlkeld (20 October 1788 – 10 October 1859) was an English missionary.
Threlkeld was son of Samuel Joseph Threlkeld, was born in England. He was well educated, and in 1814 the London Missionary Society accepted him as a missionary to the heathen. In the following year he was ordained as a missionary and sailed for Tahiti, but the illness and subsequent death of his child detained Threlkeld for a year at Rio de Janeiro, where he started a Protestant church. He left for Sydney on 22 January 1817, arrived on 11 May, after a short stay went to the South Sea Islands, and arrived at Eimeo in November.
A missionary station was formed at Raiatea and Threlkeld worked there for nearly seven years. His wife died, and being left with four children he returned to Sydney in 1824. A mission to the aborigines was founded at Lake Macquarie, 10,000 acres (40 km²) were reserved, and Threlkeld was appointed missionary. He went to live with the aborigines on their reservation, and in 1826 published Specimens of a Dialect of the Aborigines of New South Wales (author's own statement but the British Museum copy is dated 1827). In 1828 he came in conflict with the London Missionary Society which objected to his incurring unauthorized expenses in connexion with the mission. Threlkeld in reply published a pamphlet which the treasurer of the society described as "virulent". The connexion with the Missionary Society was severed and it was decided that Threlkeld should be allowed to continue his work with a salary of £150 a year from the colonial government. He was also allowed four convict servants with rations.
In 1834 he published An Australian Grammar, comprehending the Principles and Natural Rules of the Language, as spoken by the Aborigines, in the vicinity of Hunter's river, Lake Macquarie, New South Wales. The book describes the Awabakal language. This was followed in 1836 by An Australian Spelling Book in the Language spoken by the Aborigines. Threlkeld worked on for some years and began translating the New Testament into the Hunter's River language of the aborigines, but by 1842 it was realized that he was having little or no success in his mission which was then given up. Threlkeld had received a legacy from his father's estate which apparently was spent on his mission house and this reverted to the crown when the mission was abandoned.
In 1842 Threlkeld became pastor of the Congregational church at Watsons Bay, Sydney, and in 1845 he was appointed minister of the Mariners' church at Sydney and continued in this position until his death. In 1850 he published A Key to the Structure of the Aboriginal Language, and he was still working on a translation of the four Gospels when he died suddenly at Sydney. He was married twice and was survived by sons and daughters of both marriages. In 1892 An Australian Language as spoken by the Awabakal the People of Awaba or Lake Macquarie being an account of their Language, Traditions and Customs; by L. E. Threlkeld. Rearranged, condensed, and edited, with an Appendix by John Fraser, B.A., LL.D., was issued by the government of New South Wales.
Carey, Hilary. 2004. Lancelot Threlkeld and missionary linguistics in Australia to 1850. Missionary Linguistics/Lingüística Misionera: Selected Papers from the First International Conference on Missionary Linguistics, Oslo 13-16 March 2003, ed. by Otto Zwartjes and Even Hovdhaugn, 253-275. (Studies in the History of Language Sciences.) Amsterdam: John Benjamins.
Carey, Hilary M. 2010. Lancelot Threlkeld, Biraban, and the Colonial Bible in Australia. Comparative Studies in Society and History Volume 52, Issue 02, pp 447-478.