Catherine, Princess of Wales (born Catherine Elizabeth Middleton; 9 January 1982), is a member of the British royal family. She is married to William, Prince of Wales, heir apparent to the British throne.

Born in Reading, Catherine grew up in Bucklebury, Berkshire. She was educated at St Andrew's School and Marlborough College before earning a degree in art history at the University of St Andrews in Scotland, where she met Prince William in 2001 and graduated in 2005. She held several jobs and pursued charity work before their engagement was announced in November 2010. She became Duchess of Cambridge by her marriage on 29 April 2011 at Westminster Abbey. The couple have three children: George, Charlotte, and Louis. In early 2024, she was diagnosed with cancer, underwent chemotherapy, and resumed duties later that year.

Following her marriage, Catherine has undertaken royal duties and commitments in support of the British monarch. She has represented the royal family on official overseas tours and has played a significant role in various charitable activities by undertaking projects through the Royal Foundation, with her charity work primarily focusing on issues surrounding early childhood care, addiction, and art. Catherine is patron of multiple charitable and military organisations including the Anna Freud Centre, Action for Children, SportsAid, and the National Portrait Gallery. To encourage people to discuss their mental health problems, she envisioned the mental health awareness campaign Heads Together, which she launched with William and her brother-in-law Harry in April 2016.

Catherine's relationship with the media has been closely scrutinised, particularly regarding her efforts to maintain privacy amid significant media attention and public interest. The media have referred to her impact on British and American fashion as the "Kate Middleton effect". Time listed her as one of the most influential people in the world in 2011, 2012 and 2013. On 9 September 2022, she became Princess of Wales when William was created Prince of Wales by his father, King Charles III.

Catherine Elizabeth Middleton was born on 9 January 1982 at the Royal Berkshire Hospital in Reading into an upper-middle-class family with ties to the landed gentry. Her parents, Michael Middleton and Carole (née Goldsmith), were a flight dispatcher and flight attendant at British Airways, respectively. She was baptised at St Andrew's Bradfield, a local parish church, on 20 June 1982. She has two younger siblings, Philippa ("Pippa") and James. Her paternal family benefited financially from trust funds; her great-grandparents Noël and Olive Middleton played host to members of the British royal family in the 1920s through to the 1940s. Her maternal family are descended from coal miners and have been described as working-class.

Middleton's family moved from Bradfield Southend, Berkshire, to Amman, Jordan, in May 1984, where Catherine attended an English-language nursery school. When her family returned to Berkshire in September 1986, she was enrolled aged four at St Andrew's School, a private school near Pangbourne in Berkshire. She boarded part-weekly at St Andrew's in her later years. In 1987 her mother founded Party Pieces, a privately held mail order company that sold party supplies and decorations. In 1995 the family moved to the village of Bucklebury where Catherine studied at Downe House School. She was a boarder at Marlborough College, a co-educational boarding school in Wiltshire, where she showed talent in sport and was captain of the girls' field hockey team. While attending the school, she was awarded a gold Duke of Edinburgh Award. She also underwent an operation on the left side of her head, reportedly to remove a lump, during the same period.

Despite being offered a place at the University of Edinburgh, Middleton took a gap year, studying at the British Institute of Florence in Italy and travelling to Chile to participate in a Raleigh International programme. She worked as a deckhand at the Port of Southampton in the summer preceding university. She subsequently enrolled at the University of St Andrews in Fife, Scotland, where she initially studied psychology before focusing solely on art history. She worked part-time as a waitress during her studies. Middleton was an active member of The Lumsden Club, which held fundraisers and community projects each year. In 2005 she graduated from the University of St Andrews with an undergraduate Master of Arts (2:1 Hons) in art history.

In 2001 Middleton met Prince William while they were students in residence at St Salvator's Hall. She reportedly caught William's eye at a charity fashion show at the university in 2002. The couple began dating in 2003. During their second year, Middleton shared a flat with William and two friends. From 2003 until 2005, they both resided at Balgove House on the Strathtyrum estate with two roommates. They began staying at a cottage on the Balmoral estate known as Tam-Na-Ghar, which was a gift from Queen Elizabeth The Queen Mother to William shortly before her death. The property has remained a private retreat for the couple in subsequent years. In 2004 the couple briefly split but later rekindled their relationship.