He is a Brazilian international who played for two clubs in his homeland prior to his move.
Having come through the youth system at Sao Paulo, he graduated to the first team in 2008, the same year he was part of the Brazil side that won the Under-17 World Championships. That feat had also been achieved the previous year.
His time at Sao Paulo came to an end in December 2010 with a move to Internacional, a club based in Porto Alegre in the very south of the country. In 2011 and 2012 they won the local state championship and Internacional also used Oscar as a substitute in the 2010 FIFA Club World Cup, the competition to be contested by Chelsea in December, although they suffered a shock defeat by Congolese side Mazembe.
Oscar, who played international football at every level from Under-15 to Under-20, made his debut for Brazil's senior side in September 2011, coming on as a substitute in a 0-0 draw against big rivals Argentina.
He made his full debut in a win over Denmark in May and his most recent cap, his sixth, was in June when he scored his first international goal although Brazil were beaten 4-3 by Argentina in New Jersey, USA, as Lionel Messi scored a hat-trick.
Oscar's most notable moment on the international stage so far was in the final of the Under-20 World Cup in Colombia when he scored a hat-trick in a 3-2 extra-time win against Portugal.
A 5ft 10in (1.79m) attacking midfielder who can play wide, he has a reputation for good pass-and-move football, protecting the ball and choosing the right moment to play passes.
He was part of Brazil's squad at the London Olympics.