NYCFC said Wednesday that the 18-year-old winger signed a contract through the 2026 season. Magno helped Brazil win the Under-17 World Cup in 2019 and has already played 61 professional matches for Rio De Janeiro-based Vasco da Gama after making his debut as a 16-year-old.
"He is a dynamic attacker who is quick, direct and capable of playing as a winger or forward," NYCFC sporting director David Lee said.
"He is someone we believe will excite our fans, but as with any new player, particularly someone his age, we will be patient as he adapts and settles into his new environment on and off the pitch.''
Magno's signature gives NYCFC manager Ronny Deila another option in attack. The team has been without Heber, who is recovering from ACL surgery, while offseason signing Thiago Andrade remains in Brazil waiting on his work visa.
The club also recently re-signed last season's leading goal scorer Valentin Castellanos to a five-year contract extention earlier this month amid interest from Palmerias.
The Associated Press contributed to this report.