Catherine Howard (c. 1523 – 13 February 1542) was Queen of England from July 1540 until November 1541 as the fifth wife of King Henry VIII. She was the daughter of Lord Edmund Howard and Joyce Culpeper, a first 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. He secured her a place in the household of Henry's fourth wife, Anne of Cleves, where Howard 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. Henry was 49, and it is widely accepted that Catherine was about 17 at the time of her marriage to him.

Catherine was stripped of her title as queen in November 1541 and beheaded three months later on the grounds of treason for committing adultery with her distant cousin, Thomas Culpeper.

Catherine was a granddaughter of Thomas Howard, 2nd Duke of Norfolk, and his first wife, Elizabeth Tilney, but her father, Lord Edmund Howard, was the third son of the Duke, and under primogeniture, the eldest son inherited their father's estate. On her paternal side, Catherine was the niece of Thomas Howard, 3rd Duke of Norfolk, and first cousin of poet and soldier Lord Henry Howard, styled Earl of Surrey (his courtesy title as heir apparent to the Dukedom of Norfolk), and Lady Mary Howard, wife of Henry VIII's illegitimate son, Henry FitzRoy, Duke of Richmond and Somerset. Through her father's side, she was also a first cousin of Mary, George and Anne Boleyn (Catherine's aunt, Elizabeth Howard, was the mother of the Boleyn siblings). Catherine also was the second cousin of Jane Seymour, because her grandmother Elizabeth Tilney was the sister of Seymour's grandmother, Anne Say.

Catherine's mother, Joyce Culpeper, already had five children from her first husband, Ralph Leigh (c. 1476 – 1509) when she married Lord Edmund Howard, and they had another six together, Catherine being about her mother's tenth child. With little to sustain the family, her father often had to beg for the help of his more affluent relatives.

After Catherine's mother died in 1528, her father married two more times. In 1531, he was appointed Controller of Calais. He was dismissed from his post in 1539, and died in March 1539. Catherine was the third of Henry VIII's wives to have been a member of the English nobility or gentry; Catherine of Aragon and Anne of Cleves were royalty from continental Europe.

Catherine was born in Lambeth in or about 1523, although the exact date is unknown. An estimated date has been determined from the wills of family members, the known birth order of her and her siblings in various dated records, and the age range of her ladies-in-waiting, being in the same age group and often, same past household of the Dowager Duchess of Norfolk, where Catherine would spend a large portion of her childhood and adolescence. 1522 has also been suggested, based on the remarks of the French ambassador to England in 1541, who had met Catherine on many occasions in 1540 and 1541. The general consensus now among historians is that 1523 is the most likely date, 1522 is also credible, but Victorian suggestions of 1518 or 1525 are both unsustainable.

Catherine did not have a good start in life, mostly due to the routinely poor decisions of her father, Edmund Howard. Being the third son of a prominent family, Edmund's opportunities were limited to relying on the generosity of his wealthier family members and his own ability to pave his way. He was both overly proud and a spendthrift. His insult to the King and further events would continue to devolve and slowly ensnare him, and by extension, his family. Edmund developed a gambling addiction that meant the constant threat of debtors' prison, and he went into hiding on multiple occasions. In his desperate 1527 letter to Thomas Wolsey he states, "Humbly I beseech your grace to be my good lord, for without your gracious help I am utterly undone. Sir, so it is that I am so far in danger of the King's Laws by reason of the debt that I am in, that I dare not go abroad, nor come in mine own house, and am fain to absent me from my wife and my poor children ... Sir there is no help but, through your grace and your good mediation to the King's Grace."

If Cardinal Wolsey did assist the family in response to the letter written in 1527, which there is little evidence of, the funds arrived piecemeal and were probably not enough. The lowest point for the family came between 1524 and 1531, the period which roughly corresponds with Catherine Howard's birth and early years. The image this paints is of a girl likely neglected and potentially unwanted, as her birth meant a future dowry to come up with money for. Generally, Catherine's young life was filled with uncertainty and instability, so it is understandable as to why she has been often described as barely literate and generally unlearned. She clearly was not a high priority for her father, still less her education and future prospects. In 1531, help came to Catherine indirectly through the intervention of her cousin and soon-to-be queen, Anne Boleyn, whom Edmund approached regarding a position; he was assigned to be the Comptroller at Calais.