**Flávio Bolsonaro holds a commanding position in São Paulo first-round polling for Brazil’s October 4 presidential election, with recent surveys from Real Time Big Data, Datafolha, and Futura showing him at 35–39% against incumbent President Lula’s 32–33%, and all other candidates in single digits or lower.** São Paulo’s 34 million voters represent over 21% of the national electorate and have historically favored right-leaning candidates. Flávio benefits from the endorsement of popular state Governor Tarcísio de Freitas, whose own reelection bid strengthens the Liberal Party ticket, alongside the enduring Bolsonaro brand in the state. Trader consensus at 92.5% for Flávio finishing first reflects these consistent leads and limited fragmentation among remaining contenders. Late-campaign developments such as unexpected shifts in undecided voters, turnout surges among Lula’s base, or external events could still narrow the gap, though current evidence points to structural advantages for the PL candidate in this key battleground.