The election is seen as a turning point for the country. Will Luiz Inácio Lula da Silva (Workers' Party, PT) succeed in his fourth term as president, and stand against the right-wing winds in Latin America? Or will right-wing candidate and Rio de Janeiro senator Flávio Bolsonaro (Liberal Party, PL) claim victory, and Brazil follow the trend?
Former union leader Lula has a career in Brazilian politics spanning more than four decades. He has most recently served as president since 2023, having previously governed the country from 2003 to 2011. After being sentenced to prison for corruption in 2017 - a sentence that was later overturned - he made a sensational comeback to politics in 2022. Lula then defeated incumbent President Jair Bolsonaro, aged 76.
Counteract deforestation
During his last term in power, Lula has prioritized reducing economic and social gaps and successfully fought deforestation in the Amazon. According to the World Bank, poverty in the country is at a historic low - while inequality persists and national debt has grown.
He himself is confident of victory.
"I don't see how we could lose this election," Lula said recently, according to The Guardian.
Sunday's election was supposed to be a rematch between Lula and former President Jair Bolsonaro. But with Jair Bolsonaro under house arrest, Lula now faces his son, 45-year-old lawyer and senator Flávio Bolsonaro, who is following his father's political career.
Want to see a tougher take
The son has built his political image around harsher punishments, easing gun laws, and support for a crackdown on policing in Rio de Janeiro's favelas. He has also put forward a proposal to reduce the national debt by creating a fund, SOS Brazil.
Over half of the electorate consists of women, and Bolsonaro was rewarded with thunderous applause when, at a campaign rally, holding a knife, he promised to introduce chemical castration for rapists and people who have sexually abused children, reports AP.
His opponents criticize his lack of government experience, while Bolsonaro's campaign highlighted it as an advantage.
Bolsonaro has not been free from corruption allegations either - in 2018 the family was accused of suspicious bank transactions with eldest son Flávio at the center, and another corruption investigation is underway.
The election will likely be decided in a second round on October 25, according to many analysts.
