Ronaldo, who has scored 44 times this season, opened the scoring in Saturday's 5-0 win over Rayo Vallecano, but was targeted by supporters for a perceived selfishness in the second period.
However, Ancelotti has claimed that Ronaldo is fully focused on the first leg of the Champions League quarter-final against Borussia Dortmund on Wednesday.
"I see Cristiano [Ronaldo] as being highly motivated," Ancelotti told reporters at a press conference.
"The whistles he received from the crowd have now been forgotten. He was whistled because he didn't pass the ball when that was perhaps the best option. That's all there's to it.
"Cristiano is always giving his all for the club, for the team and for everyone."
Ronaldo has netted 13 times in seven Champions League games this season.