The magazine wrote that Kathryn Mayorga had claimed Ronaldo, 33, raped her in a hotel room in Las Vegas.
The Portugal international's lawyers have indicated their intention to sue Der Spiegel for its "blatantly illegal" reporting.
"No, no, no, no, no".
In his Instagram Live video, Ronaldo answered a question from a fan and said: "No, no, no, no, no - what they said today [is] fake, fake news". "The reason why I signed the contract in the first place [was] because I didn't want my name out there".
Monday's statement concludes by saying Mayorga hopes to encourage victims to report assaults "no matter how famous, wealthy or powerful they may appear to be". "I am happy, man-and all good".
Ronaldo's lawyers say they will sue Germany's Der Spiegel magazine, which originally reported the allegations.
What's more, Ronaldo reportedly insisted that he was a "good guy" except for the "one percent".
The Portuguese soccer icon allegedly raped the woman after agreeing to move to Real Madrid from Manchester United in a transfer deal worth €94 million in 2009.
"After he assaulted me, he wouldn't let me leave again", Mayorga told Der Spiegel.
According to the filing obtained by CNN, Mayorga repeatedly screamed "no" during the alleged attack, after which Ronaldo is said to have apologized, "stating he was sorry, he was usually a gentleman". He then forced her to have anal sex with him after she had rebuffed a series of advances. "Fake, fake news", a smiling Ronaldo says into the camera in English, according to the paper.
According to Mayorga, Ronaldo was on vacation on June 12, 2009, where she met him at a hotel in Sin City.
"It violates the personal rights of our client Cristiano Ronaldo in an exceptionally serious way".
At the time, Mayorga's lawyer recommended a private settlement instead of pursuing a lawsuit, and the two parties agreed upon $375,000, provided Ronaldo's lawyers read him a letter she had written.