Creid (, meaning "Believe") is the arranged soundtrack to Square's role-playing video game Xenogears. It was written by the game's composer Yasunori Mitsuda and performed by a musical ensemble dubbed Millennial Fair. It was released on April 22, 1998 in Japan by DigiCube, and re-released by Square Enix on June 29, 2005. Comprising ten tracks arranged from the Xenogears Original Soundtrack, the album is mostly done in Irish or Celtic music style, with minor influences of Japanese rock according to Mitsuda. Artists from Japan and Ireland were recruited for the project. Four of the five vocal tracks on the album were written by Junko Kudo and sung by Tetsuko Honma, while the title track "Creid" was written by Mitsuda and performed by Eimear Quinn.
The album was well received by critics, who praised both the originality of the concept as well as the execution and track selection. The work on the album inspired Mitsuda to bring Tomohiko Kira, the albums's guitarist, back to have him perform in Chrono Cross; this would eventually result in the latter game's ending song "Radical Dreamers ~ Jewel which Cannot be Stolen ~".