Arrietty, titled Arrietty the Borrower (Japanese: 借りぐらしのアリエッティ, Hepburn: Karigurashi no Arietti) in Japan and The Secret World of Arrietty in North America, is a 2010 Japanese animated fantasy film directed by Hiromasa Yonebayashi as his feature film debut as a director, animated by Studio Ghibli for the Nippon Television Network, Dentsu, Hakuhodo DY Media Partners, Walt Disney Japan, Mitsubishi, Toho and Wild Bunch. The screenplay by Hayao Miyazaki and Keiko Niwa, was based on the 1952 novel The Borrowers by Mary Norton, an English author of children's books, about a family of tiny people who live secretly in the walls and floors of a typical household, borrowing items from humans to survive. The film stars the voices of Mirai Shida, Ryunosuke Kamiki, Shinobu Otake, Keiko Takeshita, Tatsuya Fujiwara, Tomokazu Miura, and Kirin Kiki, and tells the story of a young Borrower (Shida) befriending a human boy (Kamiki), while trying to avoid being detected by the other humans.

Ghibli announced the film in late 2009 with Yonebayashi making his directorial debut. Miyazaki supervised the production as a developing planner. The voice actors were approached in April 2010, and Cécile Corbel wrote the film's score as well as its theme song. This film marks the cinematic debut of Yonebayashi, as well as the British dub marking the cinematic debut of Tom Holland.

The film was released in Japan on July 17, 2010, by Toho, and received positive reviews from critics, who praised its animation and music. It became the highest-grossing Japanese film at the Japanese box office for the year 2010, and grossed over $145 million worldwide. The film also won the Animation of the Year award at the 34th Japan Academy Prize award ceremony. Two English-language versions of the film were produced, a British dub released in the United Kingdom on July 29, 2011, by Optimum Releasing and an American dub released in North America on February 17, 2012, by Walt Disney Pictures.