The 22-year-old arrived at Manchester United’s Aon Training Complex yesterday morning after the two clubs agreed a €35m fee.
United boss Jose Mourinho said: “Victor is a very talented young player, who has a great future ahead of him at United.
“Our season last year showed us that we need options and quality to add depth to the squad and Victor is the first to join us this summer.
“I know that our fantastic group of players will welcome him as one of us.”
Lindelof has been a long-time target for United as they look to bolster their defensive options ahead of next season’s return to the Champions League.
He said: “I am thrilled to be joining Manchester United.
“I have enjoyed my time at Benfica enormously and I have learned a lot there. But I’m looking forward to playing in the Premier League at Old Trafford and for Jose Mourinho. I’m keen to get started and make my contribution to the team’s efforts to win more trophies.”
New team-mate Phil Jones insists he does not feel threatened by Lindelof’s arrival.
“We’re Manchester United, we’re going to attract the best players and the biggest players. It would be a strange summer if we weren’t signing players like that,” said Jones.
“Competition is always good. I’ve spoken to the manager, he just asks how you’re feeling, how you’re doing, just a normal conversation between player and manager.
“He’s a good man manager, he’s like that with all the players.”
In other transfer news, Roma have warned Liverpool they are not “a supermarket” and there will be no bargain buy for Mohamed Salah.
The Reds have been in talks with the Serie A side for several weeks over the Egypt international after having an opening bid of £28m (€31.8m) rejected. Roma’s valuation of the 24-year-old is far in excess of Liverpool’s and it is understood the price being quoted to the Merseysiders is more than the €40m being reported in Italy.
Sporting director Monchi, confirming the interest in Salah, said they would not be forced into selling below their valuation of the player but did not rule out Salah leaving.
“For Salah there is an offer from an English club but the price will be set by Roma, not the buyers,” he told a press conference for the presentation of new coach Eusebio Di Francesco.
“As I’ve said before, Roma is not a supermarket. Roma is a team that will represent Italy in Europe. We came second in Serie A and our idea is to keep as good a team as possible.
“At the same time no club exists that does not sell players.”
Elsewhere, Leicester have had a bid accepted for Hull defender Harry Maguire.
A fee of around £17m (€19.3m) has reportedly been agreed between the two clubs and the move could be confirmed by the weekend, subject to the player agreeing personal terms and passing a medical.
Maguire, about to enter the final year of his contract with Hull, looks set to become Craig Shakespeare’s first signing since he put pen to paper on a three-year contract as full-time Leicester boss last week.
The Foxes have been looking to bring in some cover in the centre of defence after injuries to captain Wes Morgan and Robert Huth last season exposed their lack of depth in that position.
Elsewhere, Bayern Munich have won the race to sign Corentin Tolisso from Lyon.
The 22-year-old France midfielder, who had been linked with Chelsea and Juventus, has signed a five-year contract at the Allianz Arena.
Tolisso said: “I had a wonderful time at Lyon, for which I was very grateful. Now I’m looking forward to playing for one of the best clubs in Europe.”