Eriksen has inked a three-year contract with United after passing his medical at Old Trafford.
Brentford‘s short-term contract with the 30-year-old expired last month.
Eriksen also considered returning to Thomas Frank’s side, but the allure of playing for Manchester United proved too strong.
Eriksen is United’s second summer signing after Feyenoord defender Tyrell Malacia was signed recently.
On this new journey, Christian Eriksen, said, “Manchester United is a special club, and I cannot wait to get started. I have had the privilege of playing at Old Trafford many times but to do it in the red shirt of United will be an amazing feeling.
“I have seen Erik’s work at Ajax and know the level of detail and preparation that he and his staff put into every day. It is clear that he is a fantastic coach. Having spoken with him and learned more about his vision and the way he wants the team to play, I am even more excited for the future. I still have major ambitions in the game, there is a huge amount that I know I can achieve, and this is the perfect place to continue my journey.”
John Murtough, Manchester United Football Director, commented, “Christian has been one of the best attacking midfielders in Europe throughout his career. It is no surprise that he had so many options this summer, so we are really happy that he was convinced that this is the right club for him. In addition to his outstanding technique, Christian will add valuable experience and leadership skills to the squad, and we are looking forward to seeing the benefits of these qualities on the pitch this coming season and beyond.”
He was forced to leave the Italian team after being fitted with an Implantable Cardioverter Defibrillator (ICD) following his cardiac arrest at UEFA Euro 2020. Players with ICDs are not permitted to play in Serie A.