Speculation has persisted in recent weeks that the Portugal star is pushing to leave Turin three years after his move from Real Madrid in a deal worth €112million.
A return to the Spanish capital was mooted until coach Carlo Ancelotti shot down the rumor, while possible moves to former club Manchester United, Premier League champions Manchester City and Paris Saint-Germain have also been suggested.
Ronaldo himself hit out at the media frenzy around his future in a social media post, condemning the coverage as "frivolous" and "disrespectful".
Allegri has now stated the 36-year-old wants to see out the remaining year of his contract at the Allianz Stadium.
"Ronaldo told me he's staying at Juve," Allegri said on Saturday ahead of Juve's Serie A opener against Udinese.
"He's always trained well. I read the rumours in the newspapers. He never told us he wanted to leave.
"Ronaldo is a bonus for us because he guarantees a large number of goals. Of course, we have to work as a team to bring the best out of a single player.
"Ronaldo didn't play the [pre-season] game on Thursday because we had been going through a tough week and I gave him half a day off."
Allegri returned to Juve to take over from Andrea Pirlo, having stepped down in 2019 following five hugely successful years with the Bianconeri.
He led Juve to five consecutive Serie A titles, four Coppa Italia and two Supercoppa Italiana, while also reaching two Champions League finals.
The 54-year-old said his past achievements will mean little if he cannot mount a serious challenge to reclaim the Scudetto from Inter.
"I don't have to show anything, I have to work to get results. What happened in my five years stays in the museum," he said.
"Ronaldo has won five Ballons d'Or but if this year he doesn't have a good year, they'll remember his last year at Juventus. The same goes for [Federico] Chiesa: what he did at the Euros won't count.
"We have to question ourselves every day, otherwise the conditions to win aren't created."