The 32-year-old's time at Flamengo was cut short by a dispute over unpaid wages, and he will now play the remainder of the 2012 Brasileirao with the Minas Gerais state champions
The Brazil international parted company with the Rubro-Negro on Friday, after being given permission to unilaterally rescind his contract with the club by the Rio de Janeiro Labour Court because a dispute over unpaid wages, with the 32-year-old claiming that he is owed over €16 million.
Following speculation linking Ronaldinho with Palmeiras and Chinese outfit Guangzhou Fuli, Atletico Mineiro have now confirmed that they have signed the attacker until the end of the year.
The former Barcelona ace had earlier been spotted by Arena SporTV decked out in Galo's colours at the club's training ground.
The deal is something of a coup for Belo Horizonte outfit, who had failed in their attempts to lure Inter forward Diego Forlan and Vasco midfielder Juninho Pernambucano to Belo Horizonte.
Ronaldinho, meanwhile, only joined Flamengo from AC Milan last January but his time at the Engenhao has been marked by controversy and relations between the player and the club had become increasingly strained in recent weeks, with vice-president Paulo Cesar Coutinho having last week been caught on camera slating the World Cup winner.