He made his senior debut on 8 March 2018, coming on as a second-half substitute in a 1–0 Campeonato Catarinense away loss against Hercílio Luz;[1] he only featured in one further match during the campaign, as his side achieved promotion to the Série A.
Promoted to the main squad ahead of the 2019 season, Caio made his top tier debut on 19 May of that year by starting in a 1–1 draw at Vasco da Gama.
[8] A regular starter in the left-back for the season, he helped the club to win their first-ever Copa do Brasil title.
On 10 December 2023, São Paulo notified Fluminense for a permanent transfer of Caio, agreeing to a R$ 17 million fee.
[10] On 5 January 2024, Caio signed a five-year contract with Série A reigning champions Palmeiras,[11] for a reported transfer fee of €3.8 million.