Liz and the Blue Bird (Japanese: リズと青い鳥, Hepburn: Rizu to Aoi Tori) is a 2018 Japanese animated drama film directed by Naoko Yamada and written by Reiko Yoshida, based on the Sound! Euphonium novel series written by Ayano Takeda and its eponymous anime television series adaptation. Inspired in particular by the 2017 Sound! Euphonium novel Hibike! Yūfoniamu Kitauji Kōkō Suisōgaku-bu, Haran no Dainigakushō Kōhen, the film is a spin-off sequel to the television series, focusing on the friendship of Mizore Yoroizuka and Nozomi Kasaki, two supporting characters introduced during the series' second novel (adapted as part of the second season of the anime adaptation). It is intended as a standalone work that can be fully understood without prior knowledge of the series.

The film focuses on the relationship between Mizore and Nozomi as they prepare for a concert with their high school's wind band; in parallel, it also depicts a fairy tale, from which the music piece worked on by the band is adapted, as a story within a story. Atsumi Tanezaki and Nao Tōyama, among others, reprise their voice roles as characters from the television series; most of them were re-designed to better fit the film's style and story. Liz and the Blue Bird had two composers: Kensuke Ushio, who wrote the minimal-style background music for the high school scenes, and Akito Matsuda, the composer of the television series, who wrote both the background music for the fairy tale segments, and the concert pieces performed by the characters.

It was released on April 21, 2018 in Japan, and had a limited release on November 9, 2018 in the United States. It received positive reviews from critics, with most praise going to the relationship and personalities of the two main characters, soundtrack, and animation.