Lord Thomas Howard (1511 – 31 October 1537) was an English courtier at the court of King Henry VIII. He is chiefly known for his marriage (later invalidated by Henry) to Lady Margaret Douglas (1515–1578), the daughter of Henry VIII's sister, Margaret Tudor, for which he was imprisoned in the Tower of London, where he died on 31 October 1537. The affair is referenced in a verse by his nephew, the poet Henry Howard, Earl of Surrey.

Howard was a younger son of Thomas Howard, Earl of Surrey, later 2nd Duke of Norfolk, by his second marriage to Agnes Tilney.^[1] He was a half-brother of Thomas Howard, 3rd Duke of Norfolk, son of the 2nd duke by his first marriage, and is often confused with his elder brother.

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, 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.^[2]

Howard's niece, Queen Anne, fell from power in May 1536. This undoubtedly contributed to the King's fury when in early July 1536 he learned of the marriage contract of Lord Thomas 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 Mary and Elizabeth. The couple were committed to the Tower, and on 18 July 1536 an Act of Attainder accusing 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.^[3] The death sentence was not carried out, and Lord Thomas languished in the Tower even though Lady Margaret was required to renounce their relationship by King Henry's minister Thomas Cromwell. While in the Tower, Lady Margaret fell ill, and the king allowed her to be moved to Syon Abbey under the supervision of the abbess. There are many reports that her illness was her pregnancy with Lord Thomas Howard's son and thus she was sent to the Abbey during her confinement. She was released from the Abbey on 29 October 1537. Howard remained in the Tower, where he caught an 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'. Howard was interred at Thetford Abbey.^[4]

In 1540, Lady Margaret Douglas was disgraced in a similar affair with Thomas Howard's nephew Sir Charles Howard, the son of Lord Thomas's elder half-brother Lord Edmund Howard, and a brother of Henry VIII's fifth wife, Katherine Howard.^[5]

Lord Thomas's nephew, Henry Howard, Earl of Surrey, referred to his death in a poem to "his Geraldine" (Lady Elizabeth Fitsgerald):—