The highly experienced, highly-rated 35-year-old international defender was released at the end of last season by the European Champions.
He has plenty of Premier League experience having made 55 appearances for Arsenal during a two-year stint at Highbury from 1999-2001.
Sylvinho, who will wear the number 16 shirt vacated by Kasper Schmeichel, is seen as the perfect complement to England left back Wayne Bridge.
Twice a Champions League winner, including last season when he played the entire 90 minutes of the 2-0 victory over Manchester United, and the collector of three La Liga titles whilst in Spain, Sylvinho has also played for Celta Vigo and Corinthians in a career that has seen him win six caps for Brazil.
Boss Mark Hughes is hoping that international clearance will arrive in time for his seventh summer signing to be included in the squad for the Carling Cup tie at Crystal Palace on Thursday night.
“Sylvinho has a wealth of experience at the very top level, having represented Brazil and played for some of the very top clubs in Europe,” declared the boss.
“When the chance presented itself to bring him to Manchester City as a free agent I saw it as representing excellent business for us. Sylvinho won the European Cup last season at Barcelona and he will strengthen our defensive options.”
