Shayk's first major public relationship was with Portuguese football player Cristiano Ronaldo. According to US Weekly, the pair met while on set of an Armani ad in 2010. Immediately, they became an "it" couple in Hollywood, making red carpet appearances, embracing in PDA, and were even photographed together for Vogue España's June issue in 2014.
Fans began speculating the two had split after Ronaldo didn't accompany Shayk to the premiere of Hercules in 2014, and Shayk was absent at the annual FIFA Ballon d'Or in 2015. On January 2015, US Weekly confirmed the two had called things off for good. Though neither person explicitly gave an explanation for their split, that same year Shayk told Spanish magazine Hola! that her number one relationship rule is faithfulness and honesty, leading many to believe there may have been infidelity in their relationship.