The 2009 Campeonato Paulista de Futebol Profissional da Primeira Divisão - Série A1 was the 108th season of São Paulo's top-flight professional football league. The season began on January 21 and ended on May 3. Corinthians were crowned the league champion after going through the competition undefeated. Grêmio Barueri was the top scorer with 16 goals.
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