Catherine Elizabeth Middleton was born at the Royal Berkshire Hospital in Reading, United Kingdom. She is the oldest of three children with a younger sister, Philippa ("Pippa") Charlotte and a younger brother, James William. Her mother Carole worked as a flight attendant while her father Michael worked as a flight dispatcher, both for the British Airways. They married on June 21, 1980 and founded Party Pieces, a successful mail order company that sells party supplies and decorations in 1987. Catherine and her family moved to Amman in Jordan in 1984 where her father worked for the British Airways for two and a half years. Catherine and her sister, Philippa, attended a nursery school in Jordan. In 1986, Catherine and her family returned to their home in West Berkshire, United Kingdom, where she started St. Andrew's School in Pangbourne and remained there until 1995. Catherine went on to Marlborough College Wiltshire, where she studied Chemistry, Biology and Art at A-level. She also took part in sporty activities such as tennis, hockey, netball and athletics.

At the age of 18, Catherine undertook a gap year, where she studied at the British Institute in Florence, Italy and participated in a Raleigh International programme in Chile. She also joined as a crew member on Round the World Challenge Boats in the Solent. In 2001, Catherine enrolled at the University of Saint Andrews in Fife, Scotland and graduated in 2005 with a 2:1 in History of Art. During her time at university, she continued her interest in sport by playing hockey for the university team. It was also at university where Catherine met her future husband, Prince William of Wales. Since she completed her university degree, Catherine worked for her parents' company, Party Pieces, as well as a part-time buyer in Jigsaw Junior in London.

In October 2010, during a private holiday in Kenya, her long term boyfriend, Prince William of Wales, proposed with his mother's engagement ring. The engagement was publicly announced on November 16, 2010 at a press conference and photo call in the State Rooms of St. James Palace in London. A pre-recorded TV interview with the couple followed. They married on April 29, 2011 at Westminster Abbey in London and Catherine was formally titled The Duchess of Cambridge, Countess of Strathearn, and Baroness Carrickfergus. The Duchess of Cambridge has been branded a style icon with many of her outfits selling out. Ranked #8 on Tatler's list of best dressed women in 2007. Vanity Fair named her #1 Best Dressed in 2010, 2011, and 2012, while UK Harper's Bazaar named her #1 Best Dressed in 2011. The Duchess of Cambridge is patron of Action on Addiction and the National Portrait Gallery, and royal patron of East Anglia's Children's Hospices and The Art Room. She is also a volunteer with the Scout Association.