He was 28.
Diniz was a passenger in a small airplane that crashed.
"It is with great sorrow that we received the confirmation of the tragic death of the singer and composer Gabriel Diniz who was part of the Universal Music Brasil family," Universal Music Brasil said in a statement.
UMB president Paulo Lima wrote of Diniz, "One of the greatest artists on the rise in Brazil, very talented, a beam of light, one of the most joyful people I've ever met. The Universal Music family cries for its loss. Rest in peace, my friend. May your songs be eternalized and help us soften our pain. Sending strength and comfort for all of his family and friends."
Diniz was reportedly en route to his girlfriend Karoline Calheiros' birthday party when the plane on which he was a passenger crashed in Porto Do Mato, Estância, on the coast of Sergipe, Brazil.
His final Instagram post was following a concert in Feira de Santana, Brazil.
"Always a joy to return to Feira de Santana and be greeted with such joy and with so much positive energy 🙏 🙏" he captioned the snapshots. "Thank you for the kindness…until next time God willing."