Based on Meg Cabot's 2000 young adult novel of the same name, it stars Anne Hathaway and Julie Andrews, with a supporting cast consisting of Héctor Elizondo, Heather Matarazzo, Mandy Moore, Caroline Goodall, and Robert Schwartzman.

Hathaway won the lead role over several established young actresses in her motion picture debut, while The Princess Diaries commemorated the end of Andrews's semi-retirement from acting and return to Disney films, her first since Mary Poppins (1964).

Mia learns from her estranged paternal grandmother, Clarisse, that she is the sole heir to the small European kingdom of Genovia, having inherited the throne from her recently deceased father, Philippe.

Overwhelmed by the discovery, Mia initially refuses until her mother convinces her to attend her grandmother's "princess lessons" on the condition that she need not make her final decision until the Genovian Independence Day Ball in three weeks' time.

Order of credits adapted from Variety magazine and Turner Classic Movies:[6][7][8] The Princess Diaries is based on the 2000 young adult novel of the same name by author Meg Cabot.

[30] Despite being consulted about such changes, Cabot distanced herself from the creative process to avoid compromising her vision for future novels,[16] preferring that the book and film exist in separate universes.

Chase decided that the main cast's ethnicity would remain faithful to the novel because Mia and Clarisse rule a European country, and the producer preferred to "make good movies" as opposed to only African-American films.

[29] Although Marshall believed several other candidates seemed capable of embodying Mia's comedic side, he felt only Hathaway possessed "the grace and authority" required to deliver the character's climactic speech.

[50] Cabot was initially wary of Andrews's casting, fearing the actress was too kind to play such a stern character, but ultimately felt her portrayal possessed the necessary combination of regality and grandmotherly warmth.

[67] Wendkos spent more effort revising Mia's makeover sequence than any other scene in the filming, wanting to achieve a "clearer progression from the ugly duckling to the ingenue", as per Marshall's request.

[18] The character's periwinkle state dinner gown was inspired by Victoria, Crown Princess of Sweden,[29] with Jones describing the dress as an homage to the Renaissance period and Romeo and Juliet, accessorizing it with an 18-carat diamond ring.

[18] Hathaway elaborated that, despite the makeover, her character most importantly learns that "life shouldn't be about what the rest of the world can do for her" but rather "doing everything in her power to help other people", emphasizing her emotional transformation over her physical one.

[90] Jacobs Kristal Brent Zook of The Washington Post wrote that Clarisse "must ... remake the gawky girl into a vision of regal grace" in "true Henry Higgins fashion", a character from My Fair Lady.

[91] Also writing for The Washington Post, Michael O'Sullivan similarly observed that "Most of the comedy mileage comes from the My Fair Lady scenario, in which Mia's initially frumpy appearance and klutzy manner are eliminated through a regime of industrial-strength cosmetology and boot camp-style finishing school.

[95] Some critics were concerned that the film's message might encourage younger viewers "that all awkward teens need do to find contentment is get a makeover and wait for a hitherto unknown royal grandmother to come lay a crown on their heads.

[20] A princess-themed tea party was hosted following the screening, with cast members Andrews, Hathaway, Matarazzo, Moore, Goodall, Schwartzman, Von Detten and Burbano attending.

[20] In addition to Jacobson, Disney executives Bob Iger, Richard Cook, Mark Vahradian, Chuck Viane and Oren Aviv were present, as well as actors Spencer Treat Clark, David Hasselhoff, Jennifer Love Hewitt and Michelle Trachtenberg.

[102] ABC News believes that the comedy's strong opening numbers benefited from it being one of 2001's few G-rated releases amidst several of PG-13-and R-rated films, to which parents reportedly rushed to see with their children,[114] while Allen Wan of MarketWatch joked that the family friendly rating "didn't scare off mature audiences".

[122] Ed Park, writing for The Village Voice, reviewed the film as "a modest, enjoyable fairy tale that easily outcharms its animated stablemates of the past decade", the success of which he attributed to Hathaway and Andrews' performances.

[123] Calling The Princess Diaries "an ideal family film", Kevin Thomas of the Los Angeles Times commended Marshall's ability to "mak[e] make-believe seem real" while describing Wendkos' screenplay as "skillfully adapted" and praising Andrews's performance.

[92] Robert Koehler of Variety and The Globe and Mail's Liam Lacey criticized the film for wasting the comedic opportunities offered by the book by focusing on Mia's school and romantic relationships at the expense of her grandmother's training, but considered Andrews to have been perfectly cast.

[6][85] Praising the cast's chemistry, Loren King, writing for the Chicago Tribune, credited Andrews's performance with "kick[ing] the film's class quotient up several notches".

[129] ReelViews' James Berardinelli panned the film, accusing Marshall of exploring a predictable plot "in a thoroughly uninteresting way" by "reducing characters to types and heaping mounds of saccharine and false sentiment on top".

[50][155] A sequel, The Princess Diaries 2: Royal Engagement, was released on August 11, 2004, with Marshall returning to direct, Debra Martin Chase and Whitney Houston producing, and Hathaway, Andrews, Elizondo, Matarazzo, and Miller reprising their roles alongside John Rhys-Davies, Chris Pine and Callum Blue as new characters.

[171] Lauren Hubbard, writing for Allure, believes the film "may very well be one of the single greatest makeover movies of our generation", publishing a list of "11 Beauty Lessons We Learned from The Princess Diaries".

[175] Bustle writer Veronica Walsingham believes The Princess Diaries' makeover sequence distinguishes itself from similar scenes because Mia undergoes a complete physical transformation, avoiding the trope of simply removing her glasses.

[176] The sequence's popularity has resulted in makeover films becoming something of a trademark genre for Hathaway, whose characters have undergone similar transformations in Ella Enchanted (2004),[177] The Devil Wears Prada (2006), and Les Misérables (2012).

[174][176] In her AllMovie biography of Hathaway, Rebecca Flint Marx said the actress "became a familiar face to millions of moviegoers" by proving her comedic timing in The Princess Diaries, in turn opening "a number of doors" for herself as a leading lady.

[17] Cabot remarked that the novels had actually been intended for slightly older readers, but parents who saw the G-rated film would purchase the books for their 6-7-year-old children, unintentionally exposing them to teen content.

[188] Following Marshall's death, The Daily Telegraph film critic Robbie Collin wrote that The Princess Diaries is "by no means a flawless movie", but rather "one from which a star was able to bounce out, eyes bright, teeth flashing and primed for adoration.