William Wyatt Gill (27 December 1828 – 11 November 1896) was an English missionary, active in Australia and the South Pacific region after 1851.
Gill was born in Bristol, England, son of John Gill of Barton Hill and his wife Jane, daughter of Richard Wyatt. Educated in Kingsland Congregational Chapel, Bristol, he became a member at the age of 14 and had an early interest in the ministry.
After three years study at Highbury College, London, and a year of study at New College, University of London (B.A., 1850), he was discouraged from missionary work, but his eagerness to accompany Rev. Aaron Buzacott to the Cook Islands met with approval and in June 1851 he was accepted by the London Missionary Society. On 11 July he was ordained at Spa Fields Chapel and on 15 November he arrived at Hobart Town in the mission ship John Williams where he began his missionary work in Australia.
Gill accompanied Buzacott and Henry Hopkins on missionary work at Launceston, Melbourne and Geelong. On 23 November 1851 he reached Sydney where he met Mary Layman Harrison, a pious Anglican, whom he married on 19 December. In 1852-72 Gill worked at Mangaia, Cook Islands, except for five months in 1858 at Rarotonga in charge of the institution for training native teachers and a visit to Sydney in 1862-63. In 1872 with Rev. A. W. Murray he visited the principal islands in Torres Strait and on 7 November landed the first teachers, including six Cook Islanders, at Kataw in New Guinea. In 1873 he sailed for England where he read to the Royal Geographical Society his paper 'A Visit to Torres Straits and Mainland of New Guinea'. Gill was stationed on Rarotonga from April 1877 until he retired in November 1883 after his wife died in July. On the 10th of June 1885 he married his second wife Emily, née Corrie (1843-1923). In 1889 the University of St Andrews conferred on him an honorary doctorate.