The family lived in Amman, Jordan, from May 1984 to September 1986 where her father worked for British Airways. Middleton attended an English-language nursery school. When her family returned to Berkshire in 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. She studied at Downe House School. She was a boarder at Marlborough College, a co-educational independent boarding school in Wiltshire; Middleton showed talent in sports and was captain of the women's field hockey team. After her studies, she 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. Middleton subsequently enrolled at University of St Andrews in Fife, Scotland, studying history of art. She briefly studied psychology before focusing solely on art history. She worked part-time as a waitress during her studies. While attending university, she achieved a gold Duke of Edinburgh Award. Middleton was an active member of The Lumsden Club, which held fundraisers and community projects each year. In 2005, Middleton graduated from the University of St Andrews with an undergraduate MA (2:1 Hons) in the history of art.