The Ultramarine Grosbeak (Cyanoloxia brissonii) is a passerine bird in the family Cardinalidae.
It is also known by the names of big-billed or big-billed bluebird, north-eastern bluebird, southern bluebird, true bluebird, bluebird (South of Piauí), blue guarundi, blue gurandi, gurundi -blue and tiatan.