1870 in Wales

Incumbents

• Lord Lieutenant of Anglesey – William Owen Stanley
• Lord Lieutenant of Brecknockshire – Charles Morgan, 1st Baron Tredegar
• Lord Lieutenant of Caernarvonshire – Edward Douglas-Pennant, 1st Baron Penrhyn
• Lord Lieutenant of Cardiganshire – Edward Pryse
• Lord Lieutenant of Carmarthenshire – John Campbell, 2nd Earl Cawdor
• Lord Lieutenant of Denbighshire – Robert Myddelton Biddulph
• Lord Lieutenant of Flintshire – Sir Stephen Glynne, 9th Baronet
• Lord Lieutenant of Glamorgan – Christopher Rice Mansel Talbot
• Lord Lieutenant of Merionethshire – Edward Lloyd-Mostyn, 2nd Baron Mostyn
• Lord Lieutenant of Monmouthshire – Henry Somerset, 8th Duke of Beaufort
• Lord Lieutenant of Montgomeryshire – Sudeley Hanbury-Tracy, 3rd Baron Sudeley
• Lord Lieutenant of Pembrokeshire – William Edwardes, 3rd Baron Kensington
• Lord Lieutenant of Radnorshire – John Walsh, 1st Baron Ormathwaite
• Bishop of Bangor – James Colquhoun Campbell
• Bishop of Llandaff – Alfred Ollivant
• Bishop of St Asaph – Thomas Vowler Short ; Joshua Hughes
• Bishop of St Davids – Connop Thirlwall

Events

• January — Francis Kilvert begins his famous diary.
• 14 February — In a mining accident at Morfa Colliery, Port Talbot, 30 men are killed.
• April — George Osborne Morgan introduces the Burials Bill and the Places of Worship Bill to Parliament.
• unknown dates
• *Sir George Gilbert Scott completes the restoration of Bangor Cathedral.
• *In India, Timothy Richards Lewis discovers a nematoid worm, which he calls Filaria sanguinis hominis.
• *William Thomas Lewis, 1st Baron Merthyr of Senghenydd, begins acquiring the collieries later known as the Lewis Merthyr collieries in Rhondda.
• *Jacob Lloyd is created a Knight of the Order of St. Gregory the Great by Pope Pius IX.
• *Thomas William Rhys Davids begins a series of articles for the Ceylon branch of the Royal Asiatic Society Journal.

Arts and literature

New books

• John Ceiriog Hughes — Oriau'r Haf
• David Lloyd Davies — Ceinwen Morgan neu y Rian Ddiwylliedig
• Richard Davies (Mynyddog) — ''Yr Ail Gynnig''

Sport

• Billiards — John Roberts, Sr. loses the English billiards championship after 21 years.
• Association football — Druids of Rhiwabon formed.

Births

• 13 January — Conway Rees, rugby player
• 10 March — George "Honey Boy" Evans, Welsh-born US entertainer
• 20 March — Eluned Morgan, author
• 25 March — Wallace Watts, Wales international rugby union player
• 19 June — Charles Nicholl, Wales international rugby union player
• 29 June
• *Arthur Boucher, Wales international rugby union player
• *Sir Charles Dillwyn-Venables-Llewellyn, 2nd Baronet, politician
• 14 July — Helena Jones, doctor and suffragette
• 16 July — William Henry Prosser, teacher and cricketer
• 27 July — Herbert Millingchamp Vaughan, historian
• 18 August — William Cope, 1st Baron Cope, politician and Wales international rugby player
• 27 September — Thomas Jones (T. J.), civil servant
• 22 October — J. Glyn Davies, scholar, poet and songwriter
• 3 November — Norman Biggs, Wales international rugby player
• 15 November — William Elsey, Wales international rugby player
• 20 December — Sir David Davies, politician
• 29 December — Robert Dewi Williams, teacher, minister and writer
• 31 December — David John Jones, Dean of Llandaff
• December — Ernest William Jones, steamship agent and cricketer
• date unknown
• *John William Evans, politician
• *John Hughes Morris, missionary

Deaths

• 16 March — Thomas Parry, Bishop of Barbados, 74
• 4 April — Owen Wynne Jones, writer, 42
• 15 May — Charles Hinde (army officer), soldier, 49
• 27 May — John Etherington Welch Rolls, Monmouthshire landowner and father of 1st Baron Llangattock, 63
• 23 June — Isaac Hughes, Calvinist missionary and preacher, 71/72
• 1 August — Levi Gibbon, balladeer, 92
• 17 September — Joseph David Jones, composer, 43
• 27 October — Owen Jones Ellis Nanney, politician, 80
• 29 October — Jacob Owen, architect and civil engineer, 92
• 16 November — Harry Longueville Jones, antiquary, 64