Organised by unions and leftist groups, the protest criticised what participants described as an “anti-people Congress” and voiced support for Brazilian President Luiz Inácio Lula da Silva.
Lula has warned he will impose retaliatory tariffs if the US president follows through on a pledge to raise import taxes by 50%.
Protesters also targeted São Paulo Governor Tarcísio de Freitas, an avid Trump supporter, and carried signs defending Brazil’s sovereignty.