Walter Hawken Tregellas (10 July 1831 – 28 May 1894) was a British writer of historical, biographical and other works. He was also a professional draughtsman.

Tregellas was the eldest son of John Tabois Tregellas (1792–1863), merchant at Truro, purser of Cornish mines, and author of many stories written in the local dialect of the county; John Tabois Tregellas married at St. Mary's, Truro, on 23 October 1828, Anne (1801–1867), second daughter of Richard Hawken. Walter was educated under his uncle, John Hawken, at Trevarth School, Gwennap, from 1838 to 1845, and from 1845 to 1847 at the grammar school of Truro.^[1]

Tregellas was, from youth, fond of drawing, and won prizes as an artist at the Royal Cornwall Polytechnic Society, Falmouth, from 1846 to 1848. He began his active life as a draughtsman in the War Office on 10 July 1855, was promoted to be second draughtsman on 28 February 1860, rose to be chief draughtsman on 24 May 1866, and retained the post until 1 August 1893. He died at Deal on 28 May 1894, and was buried in its cemetery on 30 May. He married at Holy Trinity Church, Brompton, on 2 November 1861, Zoe, third daughter of Charles Lucas (1808–1869). His wife survived him; they had no issue.^[1]