The Campeonato Brasileiro Série B (commonly referred to as the Brasileirão Série B, the Série B or the Brazilian Série B to distinguish it from the Italian Serie B and the Ecuadorian Serie B), and currently officially called Brasileirão Série B Betnacional by sponsorship reasons) is the second tier of the Brazilian football league system. Although not having been played annually since its founding in 1971, the competition format has changed almost every season. Since 2006 it has been contested by 20 teams in a double round-robin format with the top four teams being promoted to the Campeonato Brasileiro Série A group and the bottom four teams being relegated to the Campeonato Brasileiro Série C group.

The Brazil Serie B, officially known as Campeonato Brasileiro Série B, is the second tier of professional football in Brazil. Established in 1971, this prestigious tournament serves as a crucial platform for clubs aspiring to ascend to the top tier, the Serie A. Featuring a competitive format, Serie B showcases a diverse array of teams from across the nation, each vying for promotion to the elite level of Brazilian football.

The tournament typically runs from May to November, with clubs competing in a round-robin format. Each team plays 38 matches, facing every other team twice—once at home and once away. Points are awarded based on match results, with three points for a win, one point for a draw, and none for a loss. The top four teams at the end of the season earn promotion to Serie A, while the bottom four face relegation to the lower divisions.

Brazil Serie B is known for its passionate fan base, intense rivalries, and the emergence of future stars who often make their mark in the top leagues. The tournament not only highlights the rich football culture of Brazil but also serves as a vital stepping stone for clubs and players aiming for success on both national and international stages. With its thrilling matches and unpredictable outcomes, Brazil Serie B remains a key highlight in the Brazilian football calendar, captivating fans and fostering the next generation of football talent.