Maria João Monteiro Grancha (born 27 June 1956) is a Portuguese jazz singer. She is known for her vocal flexibility and improvisational skills. Although considered a jazz singer, she incorporates folk music, avant-garde, and electronica.

Her main musical partner is Portuguese pianist Mário Laginha. She has also worked with Aki Takase, Bobby McFerrin, David Linx, Dino Saluzzi, Gilberto Gil, Joe Zawinul, Kai Eckhardt, Lenine, Manu Katche, Ralph Towner, Trilok Gurtu, Wolfgang Muthspiel, and OGRE.

She was invited by RTP to compose an entry for Festival da Canção 2024, the Portuguese selection for the Eurovision Song Contest 2024; she performed the song "Dia" in the second semi-final on 2 March 2024, failing to qualify for the final.