The Dillwyn-Llewelyn, later Dillwyn-Venables-Llewelyn Baronetcy, of Penllergare in Llangyfelach and of Ynis-y-gerwn in Cadoxton juxta Neath both in the County of Glamorgan, is a title in the Baronetage of the United Kingdom. It was created on 20 March 1890 for John Dillwyn-Llewelyn. The son of pioneer photographer John Dillwyn Llewelyn, he was Mayor of Swansea in 1891 and Conservative Member of Parliament for Swansea from 1895 to 1900. The second Baronet briefly represented Radnorshire in the House of Commons as a Conservative and served as Lord-Lieutenant of Radnorshire. He assumed the additional surname of Venables. The third Baronet was also Lord-Lieutenant of Radnorshire.