Ten Hag has penned new terms to 2026.
The Dutchman said: "I am very pleased to have reached agreement with the club to continue working together. Looking back at the past two years, we can reflect with pride on two trophies and many examples of progression from where we were when I joined.
"However, we must also be clear that there is still lots of hard work ahead to reach the levels expected of Manchester United, which means challenging for English and European titles.
"In my discussions with the club, we have found complete unity in our vision for reaching those goals, and we are all strongly committed to making that journey together."
Dan Ashworth, United's new sporting director, also said: "With two trophies in the past two seasons, Erik has reinforced his record as one of the most consistently successful coaches in European football.
"While the club’s review of last season highlighted areas for improvement, it also reached a clear conclusion that Erik was the best partner for us to work with in driving up standards and outcomes.
"This group of players and staff have already shown they are capable of competing and winning at the top level; now we need to do it more consistently.
"With our strengthened football leadership team now in place, we are looking forward to working hand-in-hand with Erik to achieve our shared ambitions for this football club."