Catherine Howard (c.152125 13 February 1542), also spelled Katheryn Howard, was Queen of England from 1540 until 1542 as the fifth wife of Henry VIII. She was the daughter of Lord Edmund Howard and Joyce Culpeper, a cousin to Anne Boleyn (the second wife of Henry VIII), and the niece of Thomas Howard, 3rd Duke of Norfolk. Thomas Howard was a prominent politician at Henry's court, and he secured her a place in the household of Henry's fourth wife, Anne of Cleves, where she caught the King's interest. She married him on 28 July 1540 at Oatlands Palace in Surrey, just 19 days after the annulment of his marriage to Anne. He was 49, and she was between 15 and 19 years old.

Catherine was stripped of her title as queen in November 1541 and was unable to use the title in a public capacity, but she was still married to the king until she was beheaded three months later on the grounds of treason for committing adultery with her distant cousin Thomas Culpeper.

Thomas Culpeper (c. 1514 – 10 December 1541) was a courtier and close friend of Henry VIII, and related to two of his queens, Anne Boleyn and Catherine Howard. He is known to have had many private meetings with Catherine after her marriage, though these may have involved political intrigue rather than sex. A letter to him was found, written by Queen Catherine and signed, "Yours as long as life endures." Accused of adultery with Henry's young consort, Culpeper denied it and blamed the queen for the situation, saying that he had tried to end his friendship with her, but that she was "dying of love for him". Eventually, Culpeper admitted to intending to sleep with the queen, though he never admitted to having actually done so.