The Dutch trainer leaves the Eredivise giants after a successful spell which has seen him win four trophies, including the league title twice.
Ten Hag brought Ghana’s Mohammed Kudus to Ajax in the summer of 2020 and the pair have produced magic together despite the midfielder’s injury problems.
Under Ten Hag, Kudus won the double last season, and in the current campaign he is on course to win the Eredivise again.
The 53-year-old joins Manchester United on an initial three-year deal with an option to extend it for a further year.
“During the past four years at Ajax, Erik has proved himself to be one of the most exciting and successful coaches in Europe, renowned for his team’s attractive, attacking football and commitment to youth,” Manchester United’s Football Director John Murtough said.
“In our conversations with Erik leading up to this appointment, we were deeply impressed with his long-term vision for returning Manchester United to the level we want to be competing at and his drive and determination to achieve that.”
We wish Erik the best of luck as he focuses on achieving a successful end to the season at old Trafford.