The three-time Ballon d'Or winner's current deal ran until 2018 and head coach Zinedine Zidane confirmed he was on the brink of a renewal after Sunday's 3-0 La Liga win over Leganes.
Ronaldo will take part in a signing ceremony at the Santiago Bernabeu to complete the formalities of his new deal on Monday.
The 31-year-old is the latest Madrid superstar to commit his long-term future to the club after Gareth Bale secured a six-year extension a week ago, and he now appears set to conclude his top-level career in the Spanish capital.
The Sun is reporting that the deal is worth an estimated $714,000 (AUD) per week, after tax. Which over the five years works out to be a $364 million deal.
Luka Modric, Toni Kroos and Lucas Vazquez have also recently signed new contracts with Zidane's league leaders.
"I'm happy because what he must do is finish his career here," Zidane said prior to the announcement, after Ronaldo endured a frustrating outing versus Leganes where he failed to register a single shot on target.
"Cristiano is unique. What he has done and what he will do. His only intention is to finish his career here.
"I am happy because we can renew and he can finish with this white shirt as I did long ago."
Ronaldo has scored seven goals in 12 appearances so far this season and is favourite to claim a fourth Ballon d'Or on the back of Madrid and Portugal's respective triumphs in the Champions League and at Euro 2016.
He is Madrid's all-time record goalscorer, with a remarkable 371 goals in 360 games.
