Robinho has signed a short-term contract for Santos in what will be his fourth spell at the club.
The 36-year-old spent last season in Turkey with Istanbul Basaksehir, where he played 15 league games to help the club win the title for the first time in their history.
"Robinho is back!" Santos revealed on the club's official Twitter account on Saturday.
"The eternal stepover King has signed a five-month contract and agreed his return to start his fourth spell at Santos."
Robinho comes with a great wealth of experience having played for the likes of Real Madrid, Manchester City and AC Milan.
"This has always been my home," he said of Santos, who are currently seventh on the Brazil league table after 14 games.
"My objective is to help on and off the pitch and get Santos in as high a place as possible."
Robinho has played 100 times for the Brazil national team, and was part of the country's FIFA Confederation Cup winning squads of 2005 and 2009, as well as their victorious 2007 Copa America team where he was named best player of the tournament.
Robinho became the first marquee signing of the Sheikh Mansour era when the Arab bought Manchester City in September 2008, joining for a then-British transfer record fee of £32.5m from Real Madrid.
Robinho was sentenced in absentia to nine years in prison in November 2017 by an Italian court for allegedly participating in a gang rape of an Albanian woman in a Milan nightclub, although he has maintained his innocence and the case is still pending until after the completion of the appeal process.
