The 2026 Campeonato Paulista de Futebol Profissional da Primeira Divisão - Série A1 (officially the Paulistão Casas Bahia 2026 due to sponsorship reasons) was the 125th season of São Paulo's top professional football league. The competition was played from 10 January to 8 March 2026.
Corinthians are the defending champions.
Inspired by the new UEFA Champions League format, teams were divided into four pots, with four teams in each pot. Teams will face all three teams of their own pot, two of another two pots, and one of another one pot, meaning:
In the first stage, all teams will play eight matches, with the matches of teams between pots being defined by a draw. The top eight teams qualify to the quarterfinals, played in a single match, with the winners qualifying to the semifinals, also played in one match. Teams with the best campaign hold de advantage of playing at home.
The two last-placed teams of the first stage are relegated to the Campeonato Paulista Série A2.
The finals will be played in two legs, with the best placed team playing the second leg at home.
Teams were divided into four pots, and the draw for the matches took place on 11 November 2025.
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The knockout stage of the 2026 Campeonato Paulista began on 21 February 2026 with the quarter-finals and end on 8 March 2026 with the final. A total of eight teams will compete in the knockout stage.
The quarter-finals will be played in a single match at the stadium of the better-ranked team in the first phase. If the match ends in a draw, the tie will be decided via a penalty shoot-out. The semi-finals will be played with the same format as the quarter-finals. The finals will be played over two legs, with the team having the better record in matches from the previous stages hosting the second leg.
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