1820s in Wales

	1810s \| 1830s \| Other years in Wales
	Other events of the decade

This article is about the particular significance of the decade 1820 - 1829 to Wales and its people.

Incumbents

John Elias - Golygiad Ysgrythurol ar Gyfiawnhad Pechadur (1821)
Felicia Hemans - The Forest Sanctuary (1825)
Thomas Price (Carnhuanawc) - An Essay on the Physiognomy and Physiology of the Present Inhabitants of Britain (1829)
David Richards (Dafydd Ionawr) - Cywydd y Dilyw (1821)

John Ellis - Eliot (hymn tune) (1823)
Edward Jones - Hen Ganiadau Cymru (1820)
Peroriaeth Hyfryd (collection of hymns including Caersalem by Robert Edwards) (1827)
Seren Gomer (collection of hymns including Grongar by John Edwards) (1824)

1820
- 21 May - Sir Thomas Lloyd, 1st Baronet, politician and landowner (d. 1877)
1821
- 24 June - Guillermo Rawson, Argentinian politician (d. 1890)
- 16 July - John Jones (Mathetes), preacher and writer (d. 1878)
1822
- 2 March - Michael D. Jones, Patagonian settler (d. 1898)
1823
- 8 January - Alfred Russel Wallace, biologist (d. 1913)
- March - Rowland Williams (Hwfa Môn), poet and archdruid (d. 1905)
- 23 November - Sir John Evans, archaeologist (d. 1908)
1824
- date unknown - John Basson Humffray, political reformer in Australia (d. 1891)
1825
- 7 June - R. D. Blackmore, novelist (d. 1900)
1826
- 13 January - Henry Matthews, 1st Viscount Llandaff (d. 1913)
- 1 March - John Thomas, harpist (d. 1913)
- 8 May - George Osborne Morgan, lawyer (d. 1897)
- 11 May - David Charles Davies, Nonconformist leader (d. 1891)
1827
- 27 October - Joseph Tudor Hughes (Blegwryd), harp prodigy (d. 1841)
1828
- 30 January - John David Jenkins, philanthropist (d. 1876)
1829
- 27 January - Isaac Roberts, astronomer (d. 1904)

1820
- 29 January - King George III of the United Kingdom, Prince of Wales 1751-1760
- 16 June - Thomas Jones of Denbigh, Methodist preacher and writer (b. 1756)
- 27 June - William Lort Mansel, bishop and academic (b. 1753)
- 23 August - John Randles, harpist (b. 1763)
- 28 August - Henry Mills, musician (b. 1757)
1821
- 2 May - Hester Thrale, diarist (b. 1741)
- 7 August - Caroline of Brunswick, former Princess of Wales (1795-1820), 53
1822
- 30 March - David Thomas (Dafydd Ddu Eryri), poet (b. 1759)
- date unknown - Stephen Kemble, actor, brother of Sarah Siddons (b. 1758)
1823
- 26 February - John Philip Kemble, actor, brother of Sarah Siddons (b. 1757)
1825
- 24 February - Thomas Bowdler, editor (b. 1754)
- 9 June - Abraham Rees, encyclopaedist (b. 1743)
- 10 August - Joseph Harris (Gomer), Baptist minister, poet and editor (b. 1773)
1827
- date unknown - Helen Maria Williams, novelist and poet (b. c. 1761)
1828
- September - William Madocks, landowner
1829
- 26 January - Benjamin Millingchamp, collector of manuscripts (b. 1756)
- June - Elizabeth Randles, harpist (b. 1801)