The 18 year-old has signed a four-year deal with Forest to 2028.
Moreira said: “I’m really happy to be here.
“I’ve heard a lot about the Premier League and a lot about many clubs, so I’m very happy to be at Nottingham Forest, especially at a club that has a lot of tradition just like my old club.
“Me and my family are really happy about this new challenge and I can’t wait to get started and get to know the city, the people and everything about the club.”
Chief Football Officer Ross Wilson also told the club's website: “We have a number of exciting young players in our squad already and we are pleased that Eric is another young player with high potential who we are excited to add to our ranks.
“We have tracked his progress at both club and international level, and we are looking forward to his continued progression here with us.”