1880 in Wales

• Archdruid of the National Eisteddfod of Wales – Clwydfardd[1]

• Lord Lieutenant of Anglesey – William Owen Stanley[2][3][4][5]
• Lord Lieutenant of Brecknockshire – Joseph Bailey, 1st Baron Glanusk[6]
• Lord Lieutenant of Caernarvonshire – Edward Douglas-Pennant, 1st Baron Penrhyn[7]
• Lord Lieutenant of Cardiganshire – Edward Pryse[8][3]
• Lord Lieutenant of Carmarthenshire – John Campbell, 2nd Earl Cawdor
• Lord Lieutenant of Denbighshire – William Cornwallis-West
• Lord Lieutenant of Flintshire – Hugh Robert Hughes
• Lord Lieutenant of Glamorgan – Christopher Rice Mansel Talbot[9]
• Lord Lieutenant of Merionethshire – Edward Lloyd-Mostyn, 2nd Baron Mostyn[10]
• Lord Lieutenant of Monmouthshire – Henry Somerset, 8th Duke of Beaufort[11]
• Lord Lieutenant of Montgomeryshire – Edward Herbert, 3rd Earl of Powis[12]
• Lord Lieutenant of Pembrokeshire – William Edwardes, 4th Baron Kensington[3]
• Lord Lieutenant of Radnorshire – Arthur Walsh, 2nd Baron Ormathwaite

• Bishop of Bangor – James Colquhoun Campbell[13][14]
• Bishop of Llandaff – Alfred Ollivant[15]
• Bishop of St Asaph – Joshua Hughes[16][15]
• Bishop of St Davids – Basil Jones[15][17]

• 25 February – The Resurgam, an early mechanically-powered submarine, sinks off Rhyl.[18]
• 10 March – Six miners are killed in an accident at the Bedwellty Colliery, Tredegar.
• 29 April – At the United Kingdom general election, Wales elects 28 Liberal MPs. David Davies, Llandinam, is returned unopposed as member for Cardigan.
• 17 June – The rebuilt Holyhead railway station and inner harbour are officially opened by the Prince of Wales.[19]
• 15 July – 120 miners are killed in an accident at the Risca Colliery.
• 3 August – Nine miners are killed in an accident at the Bersham Colliery in Wrexham.
• 10 December – 101 miners are killed in an accident at the Penygraig Colliery, Rhondda.[20]

• Beriah Gwynfe Evans – Owain Glyndwr, one of the first full-length plays in the Welsh language, is first performed at Llanberis.[21]

National Eisteddfod of Wales held at Caernarfon (first "official" National Eisteddfod)

• Chair – W. B. Joseph, "Athrilyth"[22]
• Crown – Ellis Roberts (Elis Wyn o Wyrfai)

• Football – The Druids of Rhiwabon win the Welsh Cup for the first time.
• Rugby union – Cwmbran RFC and Crumlin RFC are founded.
• Yachting – Penarth Yacht Club is founded as Penarth Boat Club.

• 31 January – Phil Hopkins, Wales international rugby player (died 1966)
• 12 February – William Joseph Rhys, writer (died 1967)
• 17 March – Harry Grindell Matthews, inventor (died 1941)
• 8 April – Thomas Thomas, boxing champion (died 1911)
• 19 April – Jack Jenkins, Wales international rugby player (died 1971)
• 30 April – George Maitland Lloyd Davies, pacifist (died 1949)[23]
• 9 May – Thomas Scott-Ellis, 8th Baron Howard de Walden, patron of the arts (died 1946)
• 11 May – David Davies, 1st Baron Davies, politician (died 1944)
• 22 May
  • Dr Teddy Morgan, Wales international rugby player (died 1947)
  • Robert John Rowlands ('Meuryn'), journalist and poet (died 1967)
• 31 May – Edward Tegla Davies, author (died 1967)
• 22 June – Rhys Gabe, rugby player (died 1967)
• 27 July – Percy Baker, gymnast (died 1957)[24]
• 2 September – Isaac Daniel Hooson, poet (died 1948)[25]
• 15 September – William Charles Williams, VC recipient (died 1915)
• 20 September – Ernie Jenkins, Wales international rugby player (died 1958)

• 6 January – John Thomas ('Minimus'), minister and author, 71[26]
• 12 February – John Whitehead Greaves, slate mine proprietor, 72[27]
• 2 March – Charles Meredith, Tasmanian politician, 68[28]
• 12 April – Thomas Joseph Brown, Roman Catholic bishop, 81[29]
• 23 April – Robert Thomas ('Ap Vychan'), minister and writer, 70[30]
• 10 May – David Charles II, hymn-writer, 76?[31]
• 21 August – Evan Mathew Richards, politician, 68[32]
• 30 August – Mordecai Jones, industrialist, 67[33]
• 9 September – William Watkin Edward Wynne, politician and antiquarian, 78[34]