Born in Franca, São Paulo,[1] João Costa joined Botafogo-SP's youth sides in 2019, after representing Inter de Bebedouro and Francana.

He made his senior debut in the 2022 Copa Paulista, as the squad was mainly composed of under-20 players.

[2] After impressing with the under-20 squad in the 2024 Copa São Paulo de Futebol Júnior, João Costa was promoted to the main squad and started to feature regularly in the 2024 Série B under manager Paulo Gomes.

He scored his first professional goal on 4 June 2024, netting his side's second in a 2–1 away win over Santos.

[4] On 20 September 2024, João Costa was called up to the Brazil national under-20 team for a period of trainings.