Manchester United have confirmed that Casemiro has joined the club from Real Madrid on a four-year contract.
The Brazil international was presented to the Old Trafford crowd on Monday evening before the Premier League contest with Liverpool.
The Red Devils announced on Friday evening that they had come to an agreement with Los Blancos over a deal for the central midfielder.
Man United have now confirmed his arrival, subject to UK visa requirements, with the 30-year-old signing a contract until June 2026, with the option of a further 12 months.
"The opportunity to start a new challenge at Manchester United and in the Premier League is extremely exciting," Casemiro told the club's official website.
"I have worked with many great managers in my career and, having met with Erik [ten Hag] and heard his ideas, I can't wait to work closely with him, his staff and my new team-mates in the coming years.
"I'm ending one beautiful journey in Madrid whilst starting another in Manchester as determined as ever to win football matches, win trophies and make our fans proud by bringing success to this great club.
"Everybody knows the history of Manchester United, the significance of the club around the world and what it means to its supporters. To represent United is an honour and I am ready to give everything to help the team achieve our ambitions."
Casemiro gave a farewell press conference to Real Madrid on Monday before making the trip to Manchester, and he will be in the stands against Liverpool.
"After the Champions League final I spoke with my agent and we had the sense that my time here was coming towards an end. My agent told me to go on holiday and relax and then we spoke again after a month and I still had this feeling that my cycle here was coming to an end," the midfielder said during his farewell.
"When the news came out then the transfer went quickly, but we'd already had these conversations. It was very difficult to speak about this with the president, but I think being honest is one of my great values. I was always honest in these conversations.
"Those who think that don't know me. I'm not like that. If it was for money, then I could have left four or five years ago. The club always acted well with me. It was my decision. It was simply the feeling that my cycle here had come to an end. This was clear to me.
"I feel very happy about all I achieved here. When I left Sao Paulo in January of 2013, I told myself I had to give my all for this club, in games and in training. I've tried to do that. I always slept well because I know I gave my all."
The midfielder joined Real Madrid from Sao Paulo in 2013 and leaves the club having made 336 appearances for the Spanish outfit, contributing 31 goals and 29 assists in the process.
Meanwhile, he won three league titles, one Copa del Rey and five Champions League titles at Bernabeu.
Casemiro will train with his new teammates later this week and is expected to make his debut in Saturday's Premier League clash with Southampton. body check tags ::
