The Royal Preparatory Academy (or Royal Prep for short) is a school where princes and princesses go to learn various studies, particularly in royal etiquette, sports, arts, and magic. It is one of the main locations that appear in the Disney Junior series Sofia the First.
The campus includes: stables for flying horses and derby track, a large greenhouse, and a clock tower. The interior has several fancy classrooms for dancing, art, magic lessons, history, fencing, a library, and a cafeteria for eating. There are also offices for the headmistresses, a ballroom for parties, and a gym for training. The students get various textbooks as well as a map of the world for studies. These textbooks often contain things from more than one subject. Sofia's etiquette book, for instance, holds some history and magic. It is probably responsible for her being able to recognize the princesses she summons. The students generally arrive at school by pegasus-drawn carriage, since the only way to get to the academy is to fly there.
Royal Prep offers many activities for the students. They have a school band that plays at parties. Royal Prep has at least three sports teams: the Royal Prep Flying Derby Team, the Royal Redhawks Dazzleball team, and the Royal Prep ice hockey team. There are also clubs for students to join for after school activities. Any student can create a club.
It appears that Royal Prep might be an elementary level school, based on the fact that Prince Hugo's older brother, Axel, appears to be a teen and has graduated from the school, same as Hildegard's sister, Astrid. Further evidence is all the students appear to be the appropriate age range as well.
Flora, Fauna, and Merryweather serve as the headmistresses, though they also teach a few classes. Fauna teaches magic, and Flora teaches etiquette and dancing, the latter often with Professor Popov. They care well for new students, especially Sofia. Flora and Fauna helped her get concepts better by drawing pictures of her performing the actions, such as kindness or the school motto, "Rule over others as they'd rule over you." This latter picture, which also happens to be the main picture they have drawn, is rather suspicious, hinting to Sofia possibly being unusual not just due to a common background. Fauna is especially close to Sofia, calling her a good princess.
Royal Prep has a fierce inter-school rivalry with both the Junior Knights Academy, a school for knights, and Hexley Hall, a school for Sorcerers in training. In the case of the latter, there is even an unofficial holiday known as Prank Day where sorcerers from Hexley Hall use their magic to cause mischief and mayhem at Royal Prep. However, the pranks they play are far from harmless and have the potential to cause great harm to both the school and its staff and students, as well as leaving the school in disarray for weeks or even months. For example, three of the sorcerers planned to fill Royal Prep with bubbles and float it into the sky over Hexley Hall even though there were still kids inside it.
It's revealed in "One for the Books" that Royal Prep has three grades that the students are divided into: Noble Novice which is for new students and thus beginner study, Regal Rotunda which is for students that have moved on to intermediate study, and Majestic Hall which is for students that have moved on to advanced study.
Sometime prior to the day that they graduate, the graduating class gets to pick the following schools to move on to for their higher education: EverRealm Academy, a school for future Rulers and their advisors, School for Science and Alchemy, a school for Alchemists, School for Performing Arts, a school for Magical Performers, School for Royal Fashions, a school for Royal Dressmakers, School for Adventure, a school for adventurers, the Corinthian Sports School, a school for magical games and sports, and Chivalry Hall, a school for knights.
In the series finale, "Forever Royal", Sofia, James, Amber and all of their friends graduate from Royal Prep and prepare to move on. Sofia and Desmond are picked as the valedictorians and give a moving speech to their classmates, families, and teachers about how their time at the school made them what they are today and will help them later in life. The class finishes their graduation with a reprise of the school song, Royal Prep, to much applause.