After eight successive Serie A titles, Juve are eyeing European glory following five runners-up medals since their last Champions League triumph in 1996.
Ronaldo – a five-time Champions League winner who celebrated four titles with Real Madrid – was unable to help Juve past the quarter-finals in his first season last term.
However, Ronaldo believes Maurizio Sarri's Juve are poised to conquer Europe, sooner rather than later.
"After winning what I won at Madrid I needed a change and new motivation," Ronaldo told Marca.
"I still have the strength to keep winning.
"Juventus will win the Champions League. I don't know if it'll be this year or the next, but it's coming."
Ronaldo was speaking after receiving the prestigious Marca Leyenda award "for his successful career as a professional footballer and for the standing he has attained across the world."
The 34-year-old superstar made a seamless transition from Madrid to Juve, helping the Italian giants to their eighth successive Serie A crown in 2018-19.
The veteran scored 28 goals in all competitions last season, 21 of those coming in the league.