Rex: A Dinosaur's Story (Japanese: REX 恐竜物語, Hepburn: REX: Kyōryū monogatari) is a 1993 Japanese film directed by Haruki Kadokawa, based on a manga written by Masanori Hata and illustrated by Clamp. The film stars Yumi Adachi as Chie, a young girl who befriends a young Tyrannosaurus rex after it hatches from an egg co-discovered by her paleontologist father (Tsunehiko Watase).

Rex: A Dinosaur's Story was theatrically released on 3 July 1993. The film grossed ¥2.2 billion on an estimated ¥2 billion budget, making it the second-highest-grossing Japanese film of 1993 and Shochiku's highest-grossing release until it was surpassed by Peter Jackson's The Lord of the Rings: The Fellowship of the Ring (2001) in 2002. Commentators have suggested that the film aimed to capitalize on the success of Jurassic Park, which debuted a month prior. At the 17th Japan Academy Film Prize in 1994, Adachi won the Newcomer of the Year award for her performance in Rex: A Dinosaur's Story.