As a youngster, Thiago Silva trained with Fluminense but was not signed by the club when he grew older. He was, however, offered a professional contract by small Rio Grande do Sul state club RS Futebol, in the south of Brazil, and was then quickly picked up by nearby Juventude, with whom he had an excellent debut season in the First Division in 2004.

By this time Thiago Silva, formerly a right winger who also had spells in midfield and at full-back, had been converted into a centre-back. And he was good enough to attract the attention of European clubs. Firstly he played for FC Porto then became one of the shopping list of FC Dynamo Moscow. In that transfer window, Thiago move along with other Portuguese Liga player likes Derlei, Cícero, Danny Alves and Nuno Frechaut. But spells with Porto and Dynamo Moscow were blighted by injuries and illness, and he returned to Brazil to rebuild his career with the club he supported in his youth. Fluminense finished fourth in the Campeonato Brasileiro Série A, conceding only 39 goals in 38 games and winning the Copa do Brasil.

In December 2008, Thiago Silva joined Milan under a €10 million agreement. Thiago Silva was officially registered as an AC Milan player effectively from July 2009, since the club had already signed two non-EU nationals during the 2008/09 season (namely, Andriy Shevchenko^[4] and Tabaré Viudez). He made his non-competitive debut with a rossoneri jersey in a friendly match against Hannover 96 on January 21, 2009. He played all 90 minutes for the Rossoneri in that match. Since joining Milan, Thiago Silva has been very effective, praised for his occasional runs up forward. On November 8 2009 he scored his first goal in Serie A against Lazio but then in the same match he also scored an own goal.