1740 in Wales

Incumbents

• Lord Lieutenant of North Wales – George Cholmondeley, 3rd Earl of Cholmondeley
• Lord Lieutenant of Glamorgan – Charles Powlett, 3rd Duke of Bolton
• Lord Lieutenant of Brecknockshire and Lord Lieutenant of Monmouthshire – Thomas Morgan
• Lord Lieutenant of Cardiganshire – John Vaughan, 2nd Viscount Lisburne
• Lord Lieutenant of Carmarthenshire – vacant until 1755
• Lord Lieutenant of Denbighshire – Sir Robert Salusbury Cotton, 3rd Baronet
• Lord Lieutenant of Pembrokeshire – Sir Arthur Owen, 3rd Baronet
• Lord Lieutenant of Radnorshire – James Brydges, 1st Duke of Chandos
• Bishop of Bangor – Thomas Herring
• Bishop of Llandaff – Matthias Mawson ; John Gilbert
• Bishop of St Asaph – Isaac Maddox
• Bishop of St Davids – Nicholas Clagett

Events

• 6 November - Charles Wesley records in his diary a visit to the Glascott family home at Cardiff.
• date unknown - William Williams Pantycelyn becomes a deacon and is appointed curate to Theophilus Evans at Llanfaes.

Arts and literature

New books

• John Dyer - The Ruins of Rome
• Griffith Jones (Llanddowror) - Welsh Piety
• Zachariah Williams - ''The Mariners Compass Completed''

Music

• Howell Harris - ''Llyfr o Hymneu o Waith Amryw Awdwyr''

Births

• 23 February - Benjamin Evans, Congregational minister and author
• 26 December - John Williams, musician
• date unknown - Sir Watkin Lewes, politician

Deaths

• 3 April - Thomas Dominic Williams, Roman Catholic bishop, 78/9
• 7 August - Jane Brereton, poet, 55
• 3 October - Price Devereux, 9th Viscount Hereford, politician, 76
• 20 October - Sir William Williams, 2nd Baronet, of Gray's Inn, politician, 75?
• date unknown
• *Enoch Francis, Baptist
• *John Morris, youngest of the Morris brothers of Anglesey, 34