1758 in Wales

Incumbents

• Lord Lieutenant of North Wales – George Cholmondeley, 3rd Earl of Cholmondeley
• Lord Lieutenant of Glamorgan – Other Windsor, 4th Earl of Plymouth
• Lord Lieutenant of Brecknockshire and Lord Lieutenant of Monmouthshire – Thomas Morgan
• Lord Lieutenant of Cardiganshire – Wilmot Vaughan, 3rd Viscount Lisburne
• Lord Lieutenant of Carmarthenshire – George Rice
• Lord Lieutenant of Denbighshire – Richard Myddelton
• Lord Lieutenant of Pembrokeshire – Sir William Owen, 4th Baronet
• Lord Lieutenant of Radnorshire – Howell Gwynne
• Bishop of Bangor – John Egerton
• Bishop of Llandaff – Richard Newcome
• Bishop of St Asaph – Robert Hay Drummond
• Bishop of St Davids – Anthony Ellys

Events

• April – Goronwy Owen becomes headmaster of the grammar school attached to the College of William & Mary, Williamsburg, Virginia.
• 13 July – Josiah Tucker becomes Dean of Gloucester.
• October – Evan Evans (Ieuan Fardd) becomes curate of Llanllechid.
• December – The Llangibby estate passes into the hands of the Addams-Williams family when the original Williams line dies out.
• date unknown – The Welsh Charity School becomes co-educational.

Arts and literature

New books

• Peter Williams – ''Blodau i Blant''

Music

• John Thomas – Caniadau Siôn, vol. 1

Births

• 3 May – Stephen Kemble, Herefordshire-born actor, brother of Sarah Siddons
• 24 August – Sir Thomas Picton, soldier
• 3 September – Henrietta Clive, Countess of Powis
• 18 October – Theophilus Jones, lawyer and historian
• date unknown – Richard Fothergill, ironmaster
• probable – Isaac Davis, advisor to Kamehameha I of Hawaii

Deaths

• 24 January – William Wogan, religious writer, 79
• 25 January – Herbert Windsor, 2nd Viscount Windsor, 50
• 18 March – Matthew Hutton, Archbishop of Canterbury and former Bishop of Bangor, 65
• 24 March – Sir Thomas Mostyn, 4th Baronet, 53
• December – Sir Leonard Williams, 5th Baronet