There have been two baronetcies created for persons with the surname Llewellyn, both in the Baronetage of the United Kingdom.
The Llewellyn Baronetcy, of Bwllfa, Aberdare, in the County of Glamorgan, was created in the Baronetage of the United Kingdom on 31 January 1922 for David Llewellyn, a Welsh industrialist.
His second son, the third baronet (who succeeded his elder brother), was a well-known equestrian.
The Llewellyn Baronetcy, of Baglan in the County of Glamorgan, was created in the Baronetage of the United Kingdom on 20 January 1959 for Sir Godfrey Llewellyn, subsequently President of the National Union of Conservative and Unionist Associations.
His son, the second Baronet, served as Lord Lieutenant of West Glamorgan from 1987 to 1994.