The choice for Charlotte is in contrast to the nursery picked for brother Prince George, who was sent to Westacre Montessori School near the Cambridges' Norfolk home, Anmer Hall.
Kensington Palace has shared two photos of little Princess Charlotte on her first day at nursery school.
Online: "We are overjoyed that Princess Charlotte was seen carrying Cath Kidston's Pony Rucksack on her first day of nursery".
But something else was undeniably noticeable in Princess Charlotte's pictures: her uncanny resemblance to her great-grandmother, Queen Elizabeth II.
Each child's development is monitored by an allocated member of staff.
The £14,500-a-year school is owned and run by headmistress Lavinia Taylor.
The school's ethos is ethos is "for high standards, excellence and good manners".
Tuition is about $18,000 for the morning and afternoon session, according to the school's website. There are three terms in the year, so that costs families around £9,150, or about $12,200, per year.
But it appears that you get your money's worth, based on the glowing Ofsted report.
It is rated outstanding by Ofsted and described by Tatler magazine as a "hidden gem". Starting today, Charlotte will be a full-time student at Willcocks, where she will take pottery and poetry classes. Here is Charlotte posing on the steps of Kensington.
George, 4, started at St. Thomas's Battersea School in September.