Dona Miguelina is said to have passed away in the early hours of Sunday, February 21, 2021, at the age of 71.
She reportedly tested positive for Covid-19 at the end of 2020 and had been hospitalised in their home city of Porto Alegre.
Ronaldinho was very close to his late mother and occasionally had her watch his matches when he was an active footballer.
The news comes as a huge blow for the ex-Barcelona and AC Milan star, who was released from prison in Paraguay just six months ago.
The former Brazil international and his brother Roberto Assis were arrested last year for using fake passports to enter the South American country.
Ronaldinho and his brother had travelled to Paraguay to take part in a number of promotional events, however, they were found to have produced false documents.
They were subsequently arrested and put inside the maximum security Agrupacion Especializada prison.
The two-time Ballon d’Or winner, however, still managed to catch the eye of the world while in prison, with videos capturing him involved in some football activities, before his eventual release.