Star of "sertanejo", a musical genre close to "country" and very popular in Brazil, the 26-year-old singer died in the crash of a small plane-taxi in the state of Minas Gerais (south-east) .
The singer's producer, her uncle and the two pilots of the plane were also killed, said Marilia Mendonça's agent.
According to police, the probable cause of the accident was a collision with an antenna.
Many Brazilian personalities have reacted with emotion to the death of the singer, who began her career in 2014 and was one of the first women to establish herself in the "sertanejo", a genre traditionally dominated by men.
"I refuse to believe it, I refuse," tweeted footballer Neymar.
"I'm crying. I think I can't even believe it," musician Caetano Veloso wrote.
Singer Marilia Mendonca's plane wreckage in Caratinga, Brazil, November 5, 2021 - Minas Gerais Fire Department / AFP
President Jair Bolsonaro praised "one of the greatest artists of her generation".
Immensely popular in Brazil, Marilia Mendonça had 39 million subscribers on Instagram and 22 million on her YouTube channel.
Just before the accident, she posted on social networks a video of her boarding and having a meal inside the plane, announcing "a weekend of shows".
© 2021 AFP