Dic Penderyn (1808 – 13 August 1831), also known as Richard Lewis, was a Welsh labourer and coal miner who lived in Merthyr Tydfil who was involved with the Merthyr Rising of 3 June 1831. In the course of the riot he was arrested alongside Lewis Lewis, one of the primary figures in the uprising, and charged with stabbing a soldier with a bayonet. The people of Merthyr Tydfil doubted his guilt, and signed a petition for his release. However, he was found guilty and hanged on 13 August. After his death he was treated as a martyr in Merthyr and across Wales.
Penderyn was born as Richard Lewis in Aberavon, Glamorgan, Wales in 1808. He moved to Merthyr Tydfil with his family in 1819, where he and his father found work in the local mines. He was literate with some chapel schooling. His sister Elizabeth was married to the Methodist preacher Morgan Howells.
Along with Lewis Lewis (or Lewsyn yr Heliwr), his cousin, Dic Penderyn was arrested for stabbing Private Donald Black of the 93rd (Sutherland Highlanders) Regiment of Foot, using a bayonet attached to a gun. This incident was alleged to have happened outside the Castle Inn. Private Black's injuries were not fatal, and he could not identify either Lewis Lewis or Richard Lewis; nevertheless, both were convicted and sentenced to death. There is no evidence that Dic played any substantial part in the rising at all unlike Lewis who was definitely involved. Both were held in Cardiff gaol.
Lewis Lewis had his sentence commuted to transportation, largely thanks to the testimony of a Special Constable, John Thomas, whom Lewis had shielded from the rioters. The people of Merthyr Tydfil were convinced that Dic Penderyn was not responsible for the stabbing, and more than 11,000 signed a petition demanding his release; even the conservative Cambrian newspaper objected. Joseph Tregelles Price, a Quaker ironmaster from Neath, who went to console the two condemned men, was immediately convinced of Penderyn's innocence and went to Merthyr to gather evidence for this. He persuaded the trial judge that the sentence was unsafe. The Home Secretary Lord Melbourne, well known for his severity, delayed the execution for two weeks, but refused to reduce the sentence despite pleas not only from workers but the Welsh establishment. It seems the execution occurred solely because Lord Melbourne wanted at least one rebel to die as an example.