Flávio Nantes Bolsonaro (born 30 April 1981) is a Brazilian lawyer and politician, affiliated with the Liberal Party (PL) and currently a Senator for Rio de Janeiro.

A son of former President of Brazil Jair Bolsonaro and Rogéria Nantes Nunes Braga, Flávio Bolsonaro was born in Resende, Rio de Janeiro, at the Military Academy of Agulhas Negras. He holds specializations in public policy from the University Research Institute of Rio de Janeiro (IUPERJ) and in entrepreneurship from the Getúlio Vargas Foundation. Flávio Bolsonaro is married to Fernanda Antunes Figueira. Together they have two daughters: Carolina and Luiza.

Flávio Bolsonaro served as a State Deputy of Rio de Janeiro from 2003 to 2019. During his tenure, he was elected to a fourth term in 2014, securing 160,359 votes. Earlier, in his second term, he held the presidency of the Special Committee on Family Planning. His political career culminated in his election to the Senate in 2018, where he garnered 4,380,418 votes. Like his father, his political career has been marked by controversial statements.

In December 2025, Bolsonaro announced his candidacy for the 2026 Brazilian presidential election, with the endorsement of his father.

Flávio Bolsonaro was elected to his first term in the 2002 elections. He was re-elected as a state deputy in 2006, 2010, and in his last candidacy, in 2014, for the 2015–2019 period. In April 2015, he voted in favor of the appointment of Domingos Brazão to the Rio de Janeiro State Court of Accounts, an appointment that was heavily criticized at the time. Brazão would later be accused of being the mastermind behind the assassination of Marielle Franco.

On April 12, 2016, Flávio Bolsonaro and his bodyguard, who is also a military police officer, exchanged gunfire with two robbers who were holding up a car ahead of them in Rio de Janeiro's West Zone. One of the assailants was injured and fled on a motorcycle. Like other members of the Bolsonaro family, Flávio opposes what he calls "the media exploitation of human rights enforcement for the benefit of crime and criminals."

In December 2018, the newspaper O Estado de S. Paulo revealed that a report from the Council for Financial Activities Control (COAF) had identified an atypical movement of R$ 1.2 million in an account in the name of Fabrício Queiroz, a former aide to Flávio Bolsonaro. This marked the beginning of the so-called "rachadinhas case" and led the Rio de Janeiro Public Prosecutor's Office to open an investigation that lasted two years. The probe resulted in charges for the crimes of fraud, embezzlement, money laundering, and criminal organization being filed against Flávio, Queiroz, and 15 other individuals involved.

In 2021, the Superior Court of Justice (STJ) annulled the previous rulings on the case involving Queiroz and Flávio Bolsonaro. The evidence obtained by breaking the banking, tax, and telephone secrecy of the investigated parties—which had been used to support the Public Prosecutor's charges—was invalidated.