Julie Andrews as Clarisse Renaldi, Mia's grandmother and reigning Queen of Genovia Anne Hathaway as Mia Thermopolis, heir to the throne and Princess of Genovia Héctor Elizondo as Joe, Clarisse's head of security and Mia's limousine driver Heather Matarazzo as Lilly Moscovitz, Mia's eccentric and socially conscious childhood best friend Robert Schwartzman as Michael Moscovitz, Lilly's older brother who harbors romantic feelings for Mia Mandy Moore as Lana Thomas, a popular cheerleader who bullies Mia and other students Caroline Goodall as Helen Thermopolis, Mia's mother; an artist Erik von Detten as Josh Bryant, a popular, egotistical student on whom Mia develops a crush Patrick Flueger as Jeremiah Hart, a friend of Mia and Lilly's; an aspiring magician Sean O'Bryan as Patrick O'Connell, Mia's English teacher who begins to date Helen Sandra Oh as Geraldine Gupta, vice principal of Mia's school Kathleen Marshall as Charlotte Kutaway, Clarisse's secretary Mindy Burbano as Anita Harbula, Mia's gym teacher René Auberjonois as the voice of Philippe Renaldi, Mia's late father and former Prince of Genovia Gerald Hathaway, Hathaway's father, portrays Philippe in photographs and flashbacks Larry Miller as Paolo Puttanesca, Mia's hairdresser and beautician Patrick Richwood as Mr. Robutusen, Mia's neighbor; a writer Mayor Willie Brown as himself Fat Louie as himself, Mia's cat