The Portuguese superstar has joined the Saudi Arabian club after his second spell with Manchester United was ended by mutual consent in November after an explosive interview with Piers Morgan saw him criticise the club and manager Erik ten Hag.
The World Cup in Qatar saw him score in Portugal's opening group game against Ghana, his 118th goal for his country, before being dropped from the starting XI for the knockout rounds, in which the team made a quarter-final exit with a 1-0 loss to Morocco.
A European champion with Portugal in 2016, the five-time Ballon d'Or winner has scored more than 700 club goals in a career that has seen him lift the Champions League four times with Real Madrid and once, in his first spell from 2003 to 2009, with United, who he rejoined from Juventus in 2021.
Here's how the saga played out:
Sunday 13 November
Talk TV began drip-feeding excerpts of Morgan's 90-minute interview with Ronaldo, which was to be shown the following Wednesday and Thursday. In the first clip the 37-year-old said he felt "betrayed" by Manchester United and believed they were trying to force him out of the club.
Then, in The Sun, Morgan revealed that when he asked Ronaldo about current United boss Ten Hag, the Portugal forward said: "I don't have respect for him because he doesn't show respect for me." Ronaldo was also "witheringly scornful" about former United team-mate Wayne Rooney.
Monday 14 November
Further clips of the interview were released in which Ronaldo explained why he did not go on United's pre-season tour to Australia in July.
He revealed partner Georgina Rodriguez and baby daughter Bella Esmeralda were hospitalised with a "big problem", only a matter of months after the death of their new-born son, but claimed he was not fully believed by the United hierarchy.
Later in the day, in another clip, Ronaldo alleged United owners Joel and Avram Glazer "don't care" about the club.
Tuesday 15 November
The latest excerpt saw Ronaldo open up on the death of his newborn son in April, which he described as "the most difficult moment" of his life.
He said: "As you know, football carries on, so fast, many competitions, football doesn't stop. We had many, many competitions. And that moment was probably the most difficult moment that I have had in my life. Me and my family, especially Gio, that was tough."
Ronaldo arrived at the World Cup in Qatar and appeared to share a frosty exchange with United and Portugal team-mate Bruno Fernandes.
Wednesday 16 November
As millions scoured their programme planners to find out which channel Talk TV was actually on, the first part of the 'bombshell' interview finally aired. Among the new revelations were how close Ronaldo had come to joining Manchester City before he returned to Old Trafford, and that Sir Alex Ferguson had persuaded him not to join their rivals.
He also hit out at the club's owners and the appointment of Ralf Rangnick as interim boss after the sacking of Ole Gunnar Solskjaer, saying "you should bring a top manager, not a sports director".
Thursday 17 November
Part two aired with Ronaldo claiming he felt Manchester United had "cut his legs" and did not want him to "shine" or listen to advice as his relationship with the club deteriorated.
The five-time Ballon d'Or winner also addressed his future, saying: "It is hard for me to say that I will not be back to Manchester United, but regardless, let's see what's going to happen."
Former Red Devils teammate Gary Neville called for United to cancel Ronaldo's contract in the next few days.
Friday 18 November
United broke their silence, releasing a statement saying they had begun taking steps in the wake of the interview.
It read: "Manchester United has this morning initiated appropriate steps in response to Cristiano Ronaldo's recent media interview. We will not be making further comment until this process reaches its conclusion."
Monday 21 November
Ronaldo made a surprise appearance at a Portugal press conference in Qatar and described himself as "bullet-proof and iron-clad". He added: "The atmosphere is excellent, no problems, we are completely focused."
Tuesday 22 November
Manchester United announced the superstar was leaving the club, by mutual agreement, with immediate effect.
A statement read: "The club thanks him for his immense contribution across two spells at Old Trafford, scoring 145 goals in 346 appearances, and wishes him and his family well for the future.
"Everyone at Manchester United remains focused on continuing the team's progress under Erik Ten Hag and working together to deliver success on the pitch."
Ronaldo issued his own statement which read: "Following conversations with Manchester United we have mutually agreed to end our contract early.
"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. I wish the team every success for the remainder of the season and for the future."
Thursday 24 November
In the opening game of Portugal's World Cup campaign, Ronaldo scored from the penalty spot to become the first male player to score in five different World Cups.
Tuesday 6 December
Ronaldo was dropped by coach Fernando Santos for Portugal's last-16 game with Switzerland with his replacement, Goncalo Ramos, scoring a hat-trick in a 6-1 win.
Saturday 10 December
Ronaldo was again reduced to a supporting role with Santos again preferring to leave him on the bench. He came on in the second-half with little impact as Morocco progressed to the semi-finals in one of the shocks of the tournament.
Friday 30 December
A post on Al Nassr's official Instagram account, which also appeared on Ronaldo's, showed the 37-year-old Portuguese posing with the club's shirt.
An accompanying message said: "This is more than history in the making.
"This is a signing that will not only inspire our club to achieve even greater success but inspire our league, our nation and future generations, boys and girls to be the best version of themselves. Welcome cristiano to your new home alnassr-fc."
A statement on the club's official website confirmed Ronaldo had signed a contract running to 2025.
It said Ronaldo had "expressed that he is eager to experience a new football league in a different country", and added quotes from the player that said: "The vision with which Al Nassr operates is very inspiring and I am excited to join my team-mates. Let's help the team together to achieve more successes."
Ronaldo's contract is widely reported to be the most lucrative in football history with commercial and sponsorship deals included within it seeing Ronaldo set to earn an annual salary of €200 million.