Brazil participated at the 2018 Summer Youth Olympics in Buenos Aires, Argentina from 6 October to 18 October 2018. The Brazilian Olympic Committee selected a team of 79 athletes in 24 sports.
Medals awarded to participants of mixed-NOC (combined) teams are represented in italics. These medals are not counted towards the individual NOC medal tally.
Brazil qualified one archer based on its performance at the 2017 World Archery Youth Championships. Brazil later qualified a female archer based on its performance at the American Continental Qualification Tournament.
Brazil qualified two players based on the Badminton Junior World Rankings.
Brazil qualified a boys' team based on the U18 3x3 National Federation Ranking.
Brazil qualified a girls' team based on their overall ranking from the South American Youth Tour.
Brazil qualified one boat based on its performance at the 2018 World Qualification Event.
Brazil qualified a girls' combined team based on its ranking in the Youth Olympic Games Junior Nation Rankings. They also qualified a mixed BMX racing team based on its ranking in the Youth Olympic Games BMX Junior Nation Rankings and two athletes in BMX freestyle based on its performance at the 2018 Urban Cycling World Championship.
Brazil qualified a rider based on its ranking in the FEI World Jumping Challenge Rankings.
Brazil qualified a boy team at the South American U-18 Championship.
Brazil qualified two gymnasts based on its performance at the 2018 American Junior Championship.
Brazil qualified one gymnast based on its performance at the 2018 American Junior Championship.
Brazil qualified one pentathlete based on its performance at the Pan American Youth Olympic Games Qualifier.
Brazil qualified one boat based on its performance at the Americas Qualification Regatta.
Brazil qualified one boat based on its performance at the Central and South American IKA Twin Tip Qualifiers. Brazil later qualified two boats based on its performance at the Central and South American Techno 293+ Qualifiers.
Brazil qualified two table tennis players based on its performance at the Latin American Continental Qualifier.
Brazil qualified one tennis player based on the ITF World Junior Rankings.
Key
Brazil qualified two athletes based on its performance at the 2018 American Youth Olympic Games Qualifier.
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