The two-year-old was photographed by her mother, the Duchess of Cambridge, at Kensington Palace, before she took the short journey to nearby Willcocks Nursery School, where fees are just over £3,000 a term.
In the pictures, the fourth in line to the throne is wearing a coat and scarf and what appears to be a rucksack.
The nursery, which she will be attending full-time, uses lots of play to help children learn.
Founded in 1964, it offers a range of classes including French, dance, sport and music.
Each child's development is monitored by an allocated member of staff.
It is rated outstanding by Ofsted and described by Tatler magazine as a "hidden gem".
It is not the first time that pregnant Kate, 36 on Tuesday, has taken official photographs herself.
The Duchess released pictures of her newborn daughter in 2015, taken at her and William's home in Norfolk, Anmer Hall.
Kate, who accepted a lifetime honorary membership of the Royal Photographic Society last year, is a keen amateur photographer. The society recognised her "talent and enthusiasm".
In September, Charlotte's older brother, Prince George, started at Thomas's Battersea, a fee-paying independent school in south London.
He previously attended a Montessori nursery school in Norfolk, which is close to Anmer Hall.