Sunderland have signed Benfica striker Luis Hemir Silva Semedo for an undisclosed fee on a five-year deal.
The 19-year-old featured for the club's B team in the Portuguese second tier in the past two seasons.
"This is a big move for me and I am very excited to be here and meet my new team-mates," the Portugal Under-20 international told the club website.
Tony Mowbray's men finished sixth in the Championship last season before losing to Luton Town in the play-offs.
Find all the latest football transfers on our dedicated page.