The Spanish monarch looked effortlessly stylish sporting a white button down shirt, blue blazer, cuffed jeans and white sneakers as she proudly drove her children to the private institution in Madrid.
The mum-of-two, who turns 45 on Friday (15 September), was pictured beaming in the front seat of her car, while Leonor, 11, and Sofía, 10, sat in the backseat wearing their school uniforms. Princess Leonor looked sharp styling her blonde tresses up in a ponytail for her first day. After dropping off her girls, Queen Letizia was spotted chatting with fellow mums outside of the school.
Princess Leonor, who is the heir to the Spanish throne, is following in the footsteps of her father King Felipe VI, who also studied at the school. The institution was founded in 1952 and aims to "provide a solid training that prepares intellectually and ethically to play a useful profession for the individual and for society."