On 28 January 2010, Robinho returned to his home club Santos due to moving down the pecking order at Manchester City, joining them on a six-month loan deal. He had publicly stated that at Manchester City he would play every other game, and because of the upcoming World Cup, he wanted to play every game, and so returned to Brazil with Santos after declining a move to São Paulo. On his return to Santos, Robinho scored a backheel against aforementioned admirers São Paulo with five minutes to spare to complete a 2–1 victory for the Peixe. In the final match of his loan deal on 4 August, Robinho helped Santos win the Copa Brasil. Although Santos lost 2–1 to Vitória, they won the tie 3–2 on aggregate to win the competition for the first time in their history. Shortly afterwards, Robinho stated that he wanted to remain with Santos rather than return to England. Manchester City, however, refused to extend the loan deal and Santos failed to make a transfer bid.
Robinho returned to training with Manchester City in August 2010, but stated that he was seeking a move away from the club before the end of the summer transfer window on 31 August. Turkish clubs Fenerbahçe and Beşiktaş opened transfer negotiations with City, but Robinho rejected a move to Turkey, declaring that he would rather move to a club in Spain or Italy.
On 31 August 2010, Robinho moved to Milan from Manchester City for a fee of £15 million (€18M), signing a four-year contract. He made his debut as a substitute in a 2–0 defeat to newly promoted Cesena. He started his first game with Milan in their 1–0 win over Genoa. He scored his first goal in injury time against Chievo to make the score 3–1 on 16 October 2010. He continued his goalscoring form with a goal the following week in a Serie A match against Napoli on 25 October 2010. He then scored the first goal for Milan against Sampdoria, but Giampaolo Pazzini equalised on the hour mark to end as a draw.
On 4 December 2010, Robinho scored the second goal for Milan against Brescia in their 3–0 win at the San Siro. Eight days later, on 12 December, he again scored the second goal in a 3–0 victory for Milan against Bologna. He scored his first goal of 2011 against Bari to give Milan another 3–0 victory. On 29 January, he scored against Catania following a deflection from a Zlatan Ibrahimović free-kick to give Milan a 1–0 lead, then assisted Ibrahimović to give Milan a 2–0 win. On 12 February 2011, he scored his first brace for Milan against Parma to help Milan to a 4–0 win. Against Cagliari, Robinho scored a brace in the 37th week of Serie-A on 14 May 2011, leading to celebrations of the Scudetto winners after the match.