Ronaldo’s staggering 803-goal tally places him well clear of the likes of Brazil legend Pele (765), Lionel Messi (758) and Slavia Prague icon Josef Bican (720).
PopFoot has now compiled data on the top 20 players who have scored the most headers in club football this century, with Ronaldo coming out on top of the pile.
Ronaldo has scored a whopping 110 times with headers, with the Portugal captain widely revered for his remarkable heading ability.
But fans believe that the former Real Madrid star might have scored up to 140 headers across his career when his international goals are taken into consideration.
Luuk de Jong, who is currently on loan at Barcelona from Sevilla, finished behind Ronaldo in the rankings with 78 headers scored.
Posted below are the top 20 players who have scored the most headers in their club careers in the 21st century, according to PopFoot.
20. Didier Drogba (N/A): 50
19. Olivier Giroud (AC Milan): 50
18. Guillaume Hoarau (Sion): 51
17. Islam Slimani (Lyon): 51
15. Sergio Ramos (Paris Saint-Germain): 51
14. Karim Benzema (Real Madrid): 54
13. Peter Crouch (N/A): 56
12. Edinson Cavani (Manchester United): 57
11. Miroslav Klose (N/A): 58
10. Zlatan Ibrahimovic (AC Milan): 58
9. Edin Dzeko (Inter Milan): 59
8. Mario Mandzukic (N/A): 60
7. Aritz Aduriz (N/A): 63
6. Bas Dost (Club Brugge): 64
5. Radamel Falcao (Rayo Vallecano): 71
4. Fernando Llorente (Eibar): 75
3. Robert Lewandowski (Bayern Munich): 77
2. Luuk de Jong (Barcelona/Sevilla): 78
1. Cristiano Ronaldo (Manchester United): 110