Ronaldo who scored an hatrick that gave his side a 3-2 aggregate win over Atletico, appeared to mimic Atletico boss Diego Simeone, who turned to fans and grabbed his crotch during his side’s 2-0 first-leg victory.
Simeone was also charged for the same celebration, and was made to pay a fine of 20,000 euros (£17,000).
Simeone said his gesture showed he had the courage to make tough selection decisions. He apologised two days later.
UEFA will rule on the case on 21 March.
Juventus have been drawn to play Dutch side Ajax in the quarter-finals.