United and Mourinho, who was made manager in May 2016, split with the club being 19 points off first place in the Premier League.
A statement from Manchester United read: “Manchester United announces that manager Jose Mourinho has left the club with immediate effect.
“The club would like to thank Jose for his work during his time at Manchester United and to wish him success in the future.
“A new caretaker manager will be appointed until the end of the current season, while the club conducts a thorough recruitment process for a new, full-time manager.”
Reports claim Michael Carrick will be confirmed as new caretaker manager until the end of the current season.