In a tweet the Reds said: "Cristiano Ronaldo is to leave Manchester United by mutual agreement, with immediate effect."The club thanks him for his immense contribution across two spells at Old Trafford."
Ronaldo said in a statement: “I love Manchester United and I love the fans, that will never ever change.
"However, it feels like the right time for me to seek a new challenge."
The decision comes after the striker claimed he was being "pushed out" by Manchester United bosses.
In an interview with Piers Morgan, Ronaldo said he did not respect boss Erik ten Hag, and claimed Wayne Rooney was jealous of him.
The 37-year-old gave a wide-ranging interview to Talk TV's Piers Morgan that broadcast 16 and 17 November.
'Relieved': David Scott from United Youtube channel Stretford Paddock reacts to the news of Ronaldo's exit.
On 18 November, Manchester United announced they had "initiated appropriate steps" in response to the interview.
Speaking to Piers Morgan, Ronaldo criticised the way the club is run and took aim at the club's owners, manager and younger players during the interview.
The Portugal captain said he didn't "respect" manager Erik ten Hag.
"I don't have respect for him because he doesn't show respect for me. If you don't have respect for me, I'm never gonna have respect for you", he said.
Ronaldo also claimed a number of individuals at United were trying to force him out of the club and that felt "betrayed".
He also said he feels the club "hasn't evolved" since Sir Alex Ferguson stood down as manager in 2013.
"I don't know what's going on. Since Sir Alex Ferguson left I have seen not evolution in the club. The progress was zero."
The five-time Ballon d'Or winner said his former manager was the part of the reason he chose United over Manchester City last summer.
The Portugal captain spoke at a surprise press conference on Monday at the World Cup. It was his first time speaking since the Talk TV interview broadcast.
"I don't have to think about what other people think. I speak when I want", he said in response to the interview.
Ronaldo is in the Portugal squad alongside former Manchester United teammate Bruno Fernandes. He dismissed speculation about a tense atmosphere in the team.
"The atmosphere is excellent, no problems, we are completely focused. You can help by not talking about me", he said.
"I'm completely bulletproof and iron-clad."
Cristiano Ronaldo rejoined Manchester United for a second spell in August 2021 after leaving Italian side Juventus.
He was United's top scorer last season but has spent much of this season on the substitute's bench.
He left the bench before the end of the game as United beat Tottenham earlier this season and he was suspended for the team's following game away at Chelsea. The former Sporting Lisbon prodigy scored 84 goals in six Premier League seasons for Manchester United in his first stint at the club before transferring to Real Madrid in 2009. He played nine seasons in Spain before moving to Italy.
Ronaldo is now a free agent but his next destination remains unclear.