Oscar dos Santos Emboaba Júnior (Brazilian Portuguese: [oˈskaʁ duˈsɐ̃tuz ẽˈbwabɐ ˈʒũnioʁ]; born 9 September 1991), known as Oscar, is a Brazilian professional footballer who plays as an attacking midfielder for and captains Chinese Super League club Shanghai Port. He is known for his dribbling and playmaking skills.

Oscar began his career at São Paulo, and in 2009, he went to court against the club due to irregularities in his contract. After a series of controversies, he left for Internacional, where he spent the next three years of his career. His displays for club and country led to him signing for Chelsea for a fee of R$61.575 million. After four-and-a-half years with Chelsea, he signed for Chinese Super League club Shanghai SIPG (now known as Shanghai Port) for an Asian transfer record of £60 million in January 2017.

He is a Brazilian international and has represented his country at the under-20 level, at the 2012 London Olympics and at senior level. On 20 August 2011, Oscar scored three goals in the 2011 FIFA U-20 World Cup final win against Portugal, becoming the first player to score a hat-trick in the FIFA U-20 World Cup final. Oscar later described his performances at the tournament as being a "gateway to the senior side". His playing style and ability have drawn comparison to compatriot Kaká. He made his senior debut for Brazil in 2011 and was a member of the team that won the 2013 FIFA Confederations Cup and that finished fourth at the 2014 FIFA World Cup, both on home soil.