Mozart's Sister is a solo project of Caila Thompson-Hannant from Montréal, Québec. It was established in 2011.
Thompson-Hannant's musical beginnings are much accredited to the electropop introduced by her uncle. She went on to play guitar & synthesizer in the band Shapes & Sizes, which was on the Asthmatic Kitty label. She also a member of Montreal-based Miracle Fortress and Think About Life. She independently released her first EP, Dear Fear, in 2011 through Bandcamp. For the two years following this release, she garnered press attention through playing festivals such as SXSW and Pop Montreal. In February, 2013 she released her second EP, HELLO through Merok Records. She is a close friend of Claire Boucher (known as "Grimes") and the group TOPS, having performed with them several times. In June, 2014 she announced a new album, Being, for release on August 5 and released the single "Enjoy". The album "Field of Love" was released on February 17, 2017.