Ronaldo, 40, has scored over 950 goals and is expected to captain Portugal at the 2026 World Cup.
Messi, 38, an eight-time Ballon d'Or winner, led Inter Miami to the MLS Cup for the first time on Dec. 6. He was named Major League Soccer's Most Valuable Player for the second season in a row while also receiving the league's Golden Boot awarded to the top scorer.
Asked if Ronaldo is an inspiration for him, Haaland told TNT Brasil: "Of course. I think for every single football player on this planet, both Cristiano and Messi are an example of what you should do, how you should do to be able to perform at the highest level for 15 years in the greatest leagues."
While Ronaldo will continue playing until at least 42 after he extended his contract with Saudi Pro-League club Al Nassr until June 2027, Argentina captain Messi penned a new deal with Inter Miami through the end of the 2028 MLS season.
"They are both inspirational," Haaland said. "Cristiano maybe has let us in a bit more on the things he's been doing. Look at how he takes care of his body! This is amazing. He's 40, it's incredible to still be able to play [at that age]. All respect to him for being able to do that. It's not easy. "
Haaland, 25, scored his 55th goal in 54 Champions League games against Ronaldo's former club a04c-98e5-6bbd0dbbb780" href="/soccer/team?id=86">Real Madrid this week.
The goal from the penalty spot was Haaland's first at the Bernabeu and gave City a 2-1 win.
"It's special to come here and play," Haaland said after Wednesday's win.
"It's a massive club which achieved so much, especially in this competition. It's special to come here and win for the first time [for him] and score for the first time at the Bernabeu."
Haaland, meanwhile, is looking forward to playing at the World Cup for the first time next year.
- What could stop Haaland breaking Shearer's Premier League goal record?
- Why Erling Haaland will never wear gloves on the football pitch
- Erling Haaland explains why VAR suits him - and how he mastered the offside trap
He averaged two goals per game in qualifying to help Norway reach its first World Cup in 28 years.
Asked if he made an exception and had a beer or another drink during mid-season to celebrate Norway qualifying for the World Cup, Haaland said: "I don't like beers but I did.
"It was really special to finally qualify for the World Cup, first time in 28 years. I never lived when there was a World Cup in Norway. Now I finally get to live through it. A special moment.
"It's going to be amazing."
