How Green Was My Valley is a 1941 American drama film directed by John Ford, adapted by Philip Dunne from the 1939 novel of the same title by Richard Llewellyn. It stars Walter Pidgeon, Maureen O'Hara, Anna Lee, Donald Crisp, and a young Roddy McDowall.

It tells the story of the Morgans, a hard-working Welsh mining family, from the point of view of the youngest child Huw, who lives with his affectionate and kind parents as well as his sister and five brothers, in the South Wales Valleys during the late Victorian era. The story chronicles life in the South Wales coalfields, the loss of that way of life and its effects on the family.

The fictional village in the film is based on Gilfach Goch, where Llewellyn spent many summers visiting his grandfather, and it served as the inspiration for the novel. The author had claimed that he based the book on his own personal 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.

It was nominated for ten Academy Awards, winning five, famously beating Citizen Kane, Sergeant York and The Maltese Falcon for Best Picture, while Ford won for Best Director, Donald Crisp for Best Supporting Actor, Arthur Miller for Best Cinematography, and Richard Day, Nathan H. Juran and Thomas Little for Best Black-and-White Art Direction-Interior Decoration. In 1990, the film was selected for preservation in the United States National Film Registry of the Library of Congress as being "culturally, historically, or aesthetically significant". The Academy Film Archive preserved How Green Was My Valley in 1998.