The Princess Diaries is the first novel in the titular children’s book series penned by American author Meg Cabot. First published in 2000, The Princess Diaries became a New York Times bestseller and was quickly adapted into a 2001 film of the same name starring Anne Hathaway as Mia Thermopolis and Julie Andrews as Mia’s grandmother. Although the film adaptation deviates greatly from the novel, both versions of The Princess Diaries tackle the adolescent experience and utilize humor to tell a story about love, growing up, family, responsibility, and finding one’s inner strength. The American Library Association (ALA) recognized The Princess Diaries as a Best Book for Young Adults and a Quick Pick for Young Readers. The New York Public Library also included it on the list “125 Books We Love for Teens.” The series includes 11 books for young adults, as well as one volume for adult readers and a middle school series. A Publishers Weekly review posted on the author’s web site notes, "There is a school of thought that says reading should be entertaining, and this is exactly what Meg Cabot produces for us: fun. She is the master of her genre; she is the George Bernard Shaw, if not the George Eliot of [her genre]." The Quarantine Princess Diaries will be published in 2023.

Other works by this author include Princess in Love, Avalon High, and Ready or Not.

The version used for this guide is the paperback of the HarperTrophy imprint of HarperCollins Publishers.

Plot Summary

Fourteen-year-old Mia Thermopolis is in her first month of high school, and she is already flunking algebra. To make matters worse, her mother is dating her algebra teacher, and since Mia has a habit of pushing down her emotions about things that bother her, her mother gave her a diary to write in to process her feelings. Mia writes in her diary every day, documenting her life as a teenager living in Manhattan. Through her diary entries, she shares the truth about her personal frustrations with her mother and algebra, her dream of dating the handsome senior Josh Richter, and her deep fear of humiliation.

One day, Mia’s father comes to Manhattan to speak to her about something very important. Her father lives in Europe, and although Mia believes that her father is simply a politician, he tells her the truth: He is the prince of a small country called Genovia, and, by extension, Mia is the princess of Genovia. Mia’s father just discovered that he cannot have more children, which means that there is only one option for Genovia’s next heir to the throne: Mia. Mia’s life is thrown into a tailspin as she struggles to accept this news. As she tries to come to terms with her newfound title and responsibility, she feels completely ill-equipped for the role of princess. Mia is extremely self-conscious about her appearance, and she usually does everything within her power to avoid drawing attention or ridicule to herself.

Mia’s grandmother, Grandmère, comes to Manhattan to give her “princess lessons” to prepare her for the role. During their weeks together, Grandmère tries to improve Mia’s image and manners. She is highly critical of Mia and difficult to get along with, and when Grandmère takes Mia to a stylist who radically alters her appearance, Mia realizes that her grandmother is trying to change her into a completely different person. Mia is frightened and angered by the rapid changes happening in her life, and her personal relationships begin to suffer. Mia starts lying to her best friend, Lilly, to keep the truth about her royal title under wraps, but Lilly accuses her of trying to change her appearance to fit in with the popular kids at school. Mia, who historically has difficulty asserting herself and expressing her feelings, starts to find her voice and stand up for herself. With her father and her grandmother already trying to control her life, Mia realizes that she doesn’t need her friends telling her what to do, too. Mia and Lilly have a big falling out, and they stop speaking. Mia befriends a girl named Tina Hakim Baba who also has royal connections. When Mia’s longtime bully and archnemesis, Lana Weinberger, tries to bully Tina, Mia surprises herself by standing up to Lana and shoving an ice-cream cone into her sweater. Mia’s newfound confidence starts to worry others, including the principal and Lilly.

One day, disaster strikes. Thanks to Grandmère, news gets out that Mia Thermopolis of Albert Einstein High School is the Princess of Genovia, and the paparazzi descend onto her school. After weeks of desperately trying to keep her secret under wraps, Mia is thrust into the spotlight and forced to reckon with the power of the press. Suddenly, the most popular kids at school want to be her friend, including Lana. Josh, Mia’s longtime crush, breaks up with Lana and immediately asks Mia to the school’s cultural diversity dance, and she eagerly accepts. However, on the night of the dance, Josh calls the paparazzi and kisses Mia in front of their cameras to try to get his face on the front page of the New York City newspapers. Mia realizes that people like Josh and Lana will always try to use her to advance their own social standing, so she ditches Josh and joins her friends instead. Lilly apologizes for trying to boss Mia around, and Mia starts to spend more time with Lilly’s brother, Michael, who has had a crush on Mia for a long time.

Although Mia still worries about the future and her inevitable destiny as the heir to the Genovian throne, she realizes that big changes are far less scary when she has the support of her friends and family. Michael helps Mia improve her grade in algebra, and Tina, Lilly, and Mia decide to work together to use Lilly’s public access show to raise awareness of important social issues. By the end of the novel, Mia is learning to respect herself, and she decides that she is a pretty lucky girl who has a bright future ahead of her.