The 15-year-old daughter of King Felipe will begin her International Baccalaureate in the autumn at the UWC Atlantic College, located 25 kilometres (15 miles) west of Cardiff, it said in a statement.
The school, housed at the 12th-century St Donat’s Castle, is one of 18 United World Colleges (UWC) that span from Canada to Swaziland.
Founded by German educationalist Kurt Hahn, UWC schools blend rigorous education and community service and are “characterised by their open and critical spirit”, the statement said.
The two terms at the school will cost £67,000 (76,500 euros, $92,000) which will be covered by the annual allowance that King Felipe and his wife Letizia receive from the state, it added.
With students selected on merit and most on scholarships, UWC schools are funded by governments, ex-students and philanthropists.
Their alumni include fellow royals like King Willem-Alexander of the Netherlands and the Belgian heir to the throne, Princess Elisabeth.