The quirky Carmarthenshire act, made up of married singer-songwriters Ynyr Ifan and Bethan Mai, scooped the award for their second album Dos Bebés.
The couple from Pembrey also received the prize fund of £10,000 at the awards ceremony, now in its 13th year, which took place at the Wales Millennium Centre in Cardiff. They join past winners like Gruff Rhys, Gwenno and Adwaith.
The ceremony was held for the second time in front of a live public audience as part of Llais, Cardiff's flagship international arts festival which takes place between 10-15 October. The shortlisted albums were whittled down from a longlist of 130. The judges then had to choose one from 15.