Lord Thomas Howard (1511 – 31 October 1537), courtier, was a younger son of Thomas Howard, 2nd Duke of Norfolk by his second marriage to Agnes Tilney. He is chiefly known for his affair with Lady Margaret Douglas (1515–1578), the daughter of Henry VIII's sister, Margaret Tudor, for which he was imprisoned in the Tower, where he died on 31 October 1537. The affair is immortalized in verses by his nephew, the poet Earl of Surrey.
Lord Thomas was at court in 1533 when his niece, Anne Boleyn married King Henry VIII as his second wife, and helped to bear the canopy at the christening of Anne's daughter, Princess Elizabeth. In the years which followed he was often at court, and it was there that he met Lady Margaret Douglas (1515–1578), the daughter of Henry VIII's sister, Margaret Tudor, and her second husband, Archibald Douglas, 6th Earl of Angus (c.1489–1557). By the end of 1535 Lord Howard and Lady Margaret Douglas had fallen in love and become secretly engaged.
Lord Howard's niece, Queen Anne Boleyn, fell from power in May 1536. This undoubtedly contributed to the King's fury when in early July 1536 he learned of the engagement of Lord Howard and Lady Margaret since Lady Margaret was at the time next in the line of succession as a result of the King's bastardization of his daughters Princess Mary and Princess Elizabeth. Both Lord Howard and Lady Margaret were committed to the Tower, and on 18 July 1536 an Act of Attainder accusing Lord Howard of attempting to 'interrupt ympedyte and lett the seid Succession of the Crowne' was passed in both houses of Parliament. The Act sentenced Howard to death, and forbade the marriage of any member of the King's family without his permission. The death sentence was not carried out, and Howard languished in the Tower despite the fact that Lady Margaret had broken off their relationship. While in the Tower Lady Margaret fell ill with a fever, and the King allowed her to be moved to Syon Abbey under the supervision of the abbess. She was released from imprisonment on 29 October 1537. Lord Howard remained in the Tower, where he caught a fatal illness and died on 31 October 1537. There is an unsubstantiated tradition that he was poisoned. His body was given to his mother, the Dowager Duchess of Norfolk, with the stipulation that it be buried ‘without pomp’. Lord Howard was interred at Thetford Abbey.