"Mirror" is a song by Norwegian singer-songwriter Sigrid from her second studio album, How to Let Go (2022). Sigrid co-wrote the song with Caroline Ailin, Emily Warren and Sylvester Sivertsen, with the latter also producing it. She came up with the song after she had ended a relationship. It was released on 26 May 2021 as the first single from the album, marking her first release since 2019. The instrumentation consists of several music instruments, such as drums, piano and synthesizers. A disco track, it touches on themes of empowerment, freedom and self-love.