United will pay an initial £34.7m for the 23-year-old, who has penned a five-year contract with the option of a further 12 months to become Ole Gunnar Solskjaer’s first recruit ahead of the 2020-21 season.
Van de Beek was one of the star performers in Ajax’s memorable run to the semifinals of 2018-19 champions league.
However, he now follows former team-mates Frenkie de Jong, Matthijs de Ligt and Hakim Ziyech in making a big-money move away from the Johan Cruijff ArenA, having sat out Ajax’s weekend friendly against Eintracht Frankfurt.
Ajax have done some real business selling their top talent to top european clubs and making hefty profits from it.
“I cannot begin to explain how incredible an opportunity it is to join a club with such an amazing history,” he told United’s website.
“I would like to thank everyone at Ajax. I grew up there and I will always have a special bond with the club.
“I am now ready to take the next step in my career and perform at the highest level and there is no higher standard than Manchester United.
“Everyone has told me how amazing the Old Trafford atmosphere is and I am looking forward to experiencing that, once it is safe for the fans to return.
“This team has some of the best midfielders in the world and I know that I can learn from them and also bring my own strengths to the group.
“Having spoken to the manager about his vision for this team, the direction that the club is going in is hugely exciting and I cannot wait to be a part of that.”
Van de Beek has had a promising season at Ajax and now will look to shine in the likes of Bruno Fernandes and Paul Pogba and hopefully bringing the title to Old Trafford.
United start their Premier League campaign at home to Crystal Palace on September 19 – a week later than the majority of their top-flight counterparts, having been involved in the latter stages of the Europa League.