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.