Kate decided to wear a stunning red and white printed dress by Michael Kors, known as the 'Carnation dress'.
The dress may be familiar to royal fans - she rocked it during Meghan and Harry's rehearsal dinner.
This time, she cinched in her waist with a black belt and a pair of high heels.
The 37-year-old teamed up her look with her signature blow-dried locks.
It was happy faces all round as the daughter of Duchess Catherine and Prince William made her way to big school.
British reporter Rebecca English shared, "She’s very excited, I’m told - as is George at the chance to show her around the school where he has been a pupil for the last two years."