Mr Twin Sister, formerly Twin Sister, is an American band from Long Island. Their music has been described as chill wave, indie pop, dream pop, and disco. They have been compared to Cocteau Twins and Portishead. They have toured the US and Europe and have so far released two EPs and one LP.

The band members are vocalist Andrea Estella, keyboardist Dev Gupta, bassist Gabe D'Amico, guitarist-singer Eric Cardona, and drummer Bryan Ujueta. The average age of the band was 22 as of September 2010.