1804 in Wales

Centuries:	17th; 18th; 19th; 20th; 21st;
Decades:	1780s; 1790s; 1800s; 1810s; 1820s;
See also:	List of years in Wales; Timeline of Welsh history 1804 in The United Kingdom Scotland Elsewhere

This article is about the particular significance of the year 1804 to Wales and its people.

Incumbents

February 21 - The Cornishman Richard Trevithick's newly built "Penydarren" steam locomotive operates on the Merthyr Tramroad between the Penydarren Ironworks in Merthyr Tydfil and Abercynon, following several trials since February 13, the world's first locomotive to work on rails.^[1] As a result of this achievement, Samuel Homfray wins a 1000 guineas wager with Richard Crawshay as to which of them could first build a steam locomotive for use in their works.
March 7 - Inauguration of the British and Foreign Bible Society, largely at the instigation of Thomas Charles.^[2]
The Cambrian is the first newspaper published in Wales.

Edward Davies - Celtic Researches on the Origin, Traditions and Languages of the Ancient Britons
Richard Llwyd
- Gayton Wake, or Mary Dod
- Poems, Tales, Odes, Sonnets, Translations from the British
Benjamin Heath Malkin - The Scenery, Antiquities, and Biography of South Wales
Azariah Shadrach - Drws i'r Meddwl Segur
Hester Thrale - British Synonymy: or an attempt at regulating the choice of words in familiar conversation

14 January - Sir Hugh Owen, educationist (died 1881)
20 January - John Jones (Idrisyn), clergyman and author (died 1887)
2 March - Henry Davies, journalist (died 1890)
5 March - John Davies (Siôn Gymro), minister and linguist (died 1884)
31 March - Rice Rees, clergyman and historian (died 1839)
12 April (in Indiana) - George Wallace Jones, US senator and son of Welsh lawyer John Rice Jones (died 1896)^[3]
date unknown - Benjamin Price, first bishop of the "Free Church of England" (died 1896)

^ Rattenbury, Gordon; Lewis, M. J. T. (2004). Merthyr Tydfil Tramroads and their Locomotives. Oxford: Railway and Canal Historical Society. ISBN 0-901461-52-0.
^ "Our timeline". Bible Society. Archived from the original on 28 December 2010. Retrieved 26 November 2010.
^ "JONES, George Wallace, (1804 - 1896)". Biographical Directory of the United States Congress. Retrieved 10 April 2019.
^ "Yorke, Philip (1743-1804), of Erthig, Denb". History of Parliament online. Retrieved 6 February 2019.
^ Robert Thomas Jenkins. "Rees, Josiah (1744-1804), Unitarian minister". Dictionary of Welsh Biography. National Library of Wales. Retrieved 10 April 2019.