Lady Henrietta Augusta Lloyd-Mostyn (née Nevill; 18 June 1830 – 25 January 1912) was an English philanthropist and photographer who contributed to the development of the Welsh town of Llandudno.

[3] On 19 July 1855, Lady Augusta Nevill married Thomas Lloyd-Mostyn.

Lady Augusta Mostyn commissioned All Saints Church, Deganwy from the architect John Douglas as a memorial to her parents.

[4] She commissioned the Mostyn Art Gallery in Llandudno, the precursor of the current Mostyn gallery, as a headquarters for the Gwynedd Ladies' Arts Society, a society that was set up by a 'Miss Clearance Whaite' (daughter of the president of Royal Cambrian Academy of Art), Lady Mostyn donated £10.10s (which was worth ~£1500 after inflation in 2019), thus making her the founder.

[5] This is thought to have been the first art gallery in the world dedicated to exhibiting work by women.