Edmund of Langley (June 5, 1341 - August 1, 1402) was a younger son of King Edward III of England.
Like so many medieval princes, Edmund gained his identifying nickname from his birthplace: King's Langley in Hertfordshire. At the age of twenty-one, he was created Earl of Cambridge. His first wife, Isabella, was the daughter of Pedro "the Cruel" of Castile, and they had two sons, Edward and Richard, Earl of Cambridge, as well as a daughter, Constance (ancestor of queen Anne Neville). In 1385, Edmund was created Duke of York.
After Isabella's death in 1392, Edmund married Joan, a granddaughter of Joan of Kent. Joan's sister, Margaret, was the daughter-in-law of Edmund's brother, John of Gaunt. They had no children. Edmund of Langley died in his birthplace, and was buried there, in the church of the mendicant friars. His dukedom passed to his eldest son, Edward. However, it was through the marriage of his younger son, Richard, that the Yorkist faction in the Wars of the Roses made its claim on the throne.