The Brazil national under-20 football team, also known as Brazil Sub-20 or Seleção Sub-20, represents Brazil in association football at this age level and is controlled by the Brazilian Football Confederation (CBF).

The team has won the South American Youth Championship a record twelve times and is the second most successful nation in the FIFA U-20 World Cup, having won the competition five times. It also plays in unofficial under-19 and under-21 tournaments, such as the Toulon Tournament, of which Brazil is an eight-time winner.

Notable players that came through the ranks and went on to play for the senior team include Ronaldinho, Kaká, Rivaldo, Romário, Marcos, Roberto Carlos, César Sampaio, Cláudio Taffarel, Bebeto, Dida, Neymar, Dani Alves, Maicon, Adriano, Júlio Baptista, Luisão, Alex, Giovane Élber, Leonardo, Müller, Silas, Marcelo, David Luiz, Willian, Jô and Lucas Moura, among others.

Brazylia U20 to młodzieżowa reprezentacja Brazylii, biorąca udział w rozgrywkach piłkarskich. Reprezentuje ona Brazylię w kategorii wiekowej poniżej 20 lat.