The five-time Ballon d'Or winner was controversially dismissed following a clash with Jeison Murillo at Mestalla, although Juve went on to triumph through penalties from Miralem Pjanic either side of half-time.
Ronaldo will sit out Juve's match against Swiss champions Young Boys but the decision from UEFA's Control, Ethics and Disciplinary Body means the ex-United favourite will be able to make his latest return to Old Trafford on October 23.
United's Champions League triumph in 2007-08 marked Ronaldo's first success and he went on to win the title a further four times with Real Madrid.
He scored in both legs, including the decisive goal in Manchester, as Madrid beat United 3-2 on aggregate in the last 16 of the 2012-13 edition.
Juve will face United at Old Trafford on October 23, before taking them on in Turin on November 7.
Following the red card, Leonardo Bonucci indicated that his team-mate was left "angry" at the decision, while Juve boss Massimiliano Allegri believes VAR would have saved the star.
Miralem Pjanic went one step further, despite scoring the two penalties that won Juve the game, and insisted that the red card was "absurd".
"Football is a strange game. We could have been 4-0 up after the opening period, then came that absurd sending off," Pjanic said, via the club's website.
There was a possibility that it might have been extended to two games, meaning he would have had to sit out the Old Trafford clash.
Former Premier League referee Mark Clattenburg believes Ronaldo's red card was harsh - he claims he would have shown both Murillo and the Portuguese a yellow, and awarded Valencia a free-kick - and thinks a one-match ban will suffice.
Writing in the Daily Mail, he said: "The contact looked very slight and I cannot see how the additional assistant, standing some 20 yards away, could deem it violent conduct.
"If I had been officiating this game, I would have given Valencia a free-kick and shown a yellow card to each player. Ronaldo will serve a one-match ban but anything more would be harsh."