Born in Maceió, Alagoas, Kaio joined Coritiba's youth setup in 2018, aged 14.

[2] Kaio made his professional debut on 18 January 2023, coming on as a late substitute for Alef Manga in a 3–0 Campeonato Paranaense away win over Foz do Iguaçu.

[3] Eleven days later, in his first match as a starter, he scored his side's second in a 2–2 home draw against Azuriz.

[5] On 31 January 2024, Kaio joined Portuguese Primeira Liga club Vitória de Guimarães on loan until the end of the 2023–24 season, with an optional buy-clause, reported to be around €1.5 million.

[6][7] On 21 January 2025, Saudi club Al-Hilal announced the signing of Kaio on a three-and-a-half-year contract for a reported fee of €10 million, following Vitória's activation of the buyout clause.