Bruno Fernandes says he will give “everything” to bring “success and trophies” to Manchester United after joining on a five-and-a-half year deal from Sporting Lisbon.
The midfielder, 25, has joined for 55m euros (£47m) but add-ons could increase the overall cost to 80m euros (£67.7m).
“For me to now play for Manchester United feels incredible,” said Portuguese international Fernandes.
Manager Ole Gunnar Solskjaer said the midfielder was a “fantastic addition”.
Fernandes’ move is the biggest in the Premier League so far during the January transfer window – with the deadline at 23:00 GMT on Friday. He follows Cristiano Ronaldo, Nani and Marcos Rojo in joining Manchester United from Sporting.
His deal, which runs until 2025, also has an option to extend for a further year.
“My love of Manchester United really started when I used to watch Cristiano Ronaldo play and ever since then I have been a big fan of this great club,” added Fernandes.
“I have worked hard to get to this moment and I can promise the fans that I will give everything for the badge to help bring us more success and trophies.
“I want to thank Sporting for everything they have done for me. It is surreal to hear the nice words that have been said about me from players that used to play for this team.”