The heir to the Spanish throne is to study in the Vale of Glamorgan from this summer, at UWC Atlantic College near Llantwit Major.
Princess Leonor de Borbob, 15 is the elder of two daughters of King Felipe VI and Queen Letizia, will attend Atlantic College, based at St Donats Castle.
The princess will begin her £67,000 two-year course at the boarding school this summer, ahead of her 16th Birthday in October.
She applied for a place through the United World Colleges Spanish Committee - which is conducted anonymously, along with all other candidates.
"We are looking forward to welcoming HRH Princess Leonor of Asturias as one of the Spanish nominees to attend UWC Atlantic in 2021," said Peter T. Howe, principal of the college.
Jens Waltermann, executive director of UWC International, added: "The princess will join 4,500 other students from 155 countries, and from a diverse range of backgrounds, who will be studying at one of our 18 schools.