Telles, 27, has signed a four-year contract at Old Trafford and joins the Premier League club for a fee of £15.4million.
The left-back boasted a superb record for Porto, scoring 26 goals and making more than 50 assists for the club.
Reacting to Manchester United’s deal for Telles, Solskjaer said: ‘
First and foremost, I welcome Alex to United.
He is a player we have been tracking for some time and his performances over the past few years are exactly what we are looking for.
He is a fighter and a winner and will add real determination and competition to the squad.
Alex has the qualities, both as a player and as a person, that we want here at Manchester United.‘
Telles, meanwhile, says it is a ‘huge honour’ to join Manchester United after becoming the club’s second summer signing following Donny van de Beek.
‘To join a club with the prestige of Manchester United is a huge honour,’ Telles said.
‘You have to work hard to get to this moment in your career and now I am coming to this club, I can promise that I will give everything in my heart to be a success here.
I won many trophies at Porto and I want to continue that at United. The manager has a clear plan and direction for this team and I can’t wait to pull on the famous shirt.‘
Manchester United are also set to announce the signing of former PSG striker Edinson Cavani.