The 2019 Campeonato Paulista de Futebol Profissional da Primeira Divisão - Série A1 was the 118th season of São Paulo's top professional football league. Corinthians became the champion.

• In the first stage the sixteen teams were drawn, with seeding, into four groups of four teams each, with each team playing once against the twelve clubs from the other three groups. After each team had played twelve matches, the top two teams of each group qualified for the quarter-final stage.
• After the completion of the first stage, the two clubs with the lowest number of points, regardless of the group, were relegated to the Campeonato Paulista Série A2.
• Quarter-finals, semi-finals and finals were played in a two-legged home and away fixture, with the best placed first stage team playing the second leg at home.^[1]
• In case of a draw in any knockout stage match, the winner was decided via a penalty shoot-out.
• The two highest-placed teams not otherwise qualified qualified for the 2020 Copa do Brasil.
• The top three highest-placed teams in the general table at the end of the competition who were not playing in any level of the national Brazilian football league system qualified for the 2020 Campeonato Brasileiro Série D. The clubs eligible for promotion were Red Bull Brasil, São Caetano, Novorizontino, Ferroviária, Mirassol, and Ituano.

Source: Regulamento do Paulistão 2019