He scored eight goals in 33 appearances as Vasco secured promotion to Brazil's top flight in 2022.

"I am very happy and excited to be here. I know Forest is a big club," said Santos.

"They have good players and play good football, which is important to me. It has always been my dream to play in the Premier League and I can't wait to enjoy playing."

In February, Santos captained Brazil to victory in the South American Under-20 Championship, finishing the tournament as joint top scorer with six goals.

He was rewarded with his first senior call-up in March, making his debut against Morocco.

He has yet to make a senior appearance for Chelsea but featured regularly for Mauricio Pochettino's side in pre-season.

Santos becomes Forest's fifth signing of the summer following the arrivals of Anthony Elanga, Matt Turner, Ola Aina and Gonzalo Montiel.