Richard Dafydd Vivian Llewellyn Lloyd, known by his pen name Richard Llewellyn, was a British novelist of a Welsh background, who is best remembered for his 1939 novel How Green Was My Valley, which chronicles life in a coal mining village in the South Wales Valleys.

How Green Was My Valley is a 1939 novel by Richard Llewellyn, narrated by Huw Morgan, the main character, about his Welsh family and the mining community in which they live. The author had claimed that he based the book on his own experiences but this was found to be untrue after his death; Llewellyn was English-born and spent little time in Wales, though he was of Welsh descent. Llewellyn gathered material for the novel from conversations with local mining families in Gilfach Goch.