João Rego progressed through the ranks of Initiates, Youths, Juniors, U-23, and B Team while wearing the Sacred Mantle. In the 2021/22 season, he won the title of National Junior Champion.
On May 12, 2024, in a match of the 33rd round of the National Championship against Arouca, at Estádio da Luz, João Rego made his debut for Benfica's first team at the age of 18.
The attacking midfielder has earned caps for Portugal's youth national teams at the U-17, U-18, U-19, and U-20 levels.