Born in Rio de Janeiro, Welliton joined Corinthians' youth setup in 2015, from Vasco da Gama.
On 3 July 2019, after being rarely used in the under-20 squad, he terminated his contract and joined Oeste.
[1] Welliton made his first team debut for Oeste on 31 August 2019, coming on as a late substitute for Bruno Lopes in a 0–0 Série B home draw against Sport Recife.
[2] He featured sparingly for the side in the following two years, suffering two relegations during the 2020 season.
[3] He made his first team debut for Braga on 20 March of the following year, replacing Helinho in a 1–1 Campeonato Paulista home draw against Palmeiras.