United showed they were suffering no hangover from their shock defeat at West Ham to ensure they will go into Christmas as leaders from Chelsea.
Ronaldo capped a magnificent display by scoring the opener in the 59th minute and, after Scholes volleyed home from 25 yards five minutes later, he wrapped up the points in the closing stages.
• Fergie: Mourinho got it wrong
If United could have picked out a fixture in which to bounce back from their Upton Park reversal then it would have been Villa, who have failed to beat them in the league for more than 11 years.
The Red Devils took the first half to warm up against a combative Villa side but in the second half they produced some superb football.
Ronaldo ignored the taunts of the Villa fans to torment the home side and one had sympathy for recalled full-back Aaron Hughes who was turned inside out.
Villa have now gone seven games without a win and for all their endeavours, it is evident they require an injection of quality in the January transfer window.
Before the kick-off, former Villa manager Ron Saunders, who guided the team to the League Championship in the early 1980s, was given a standing ovation on his first return to the ground for more than 20 years.
Villa made a lively start and were combative in the centre of the park through Craig Gardner, making his first start of the season, and Gavin McCann who passed a late fitness test on his hamstring injury.
United gradually started to come into the game and Villa centre-back Gary Hill blocked a left-footed drive from Ji-Sung Park and a long-range attempt from Ronaldo.
But after 15 minutes the woodwork came to United's rescue when a free-kick from Barry was flicked on by Chris Sutton to Gardner, whose header clipped the outside of a post.
United centre-back Nemanja Vidic became the first player to be yellow-carded a minute later for hauling down the lively Gabriel Agbonlahor in full flight.
Park, in his first league start since August, looked lively in the early stages but would have been disappointed with the accuracy of his finish from United's first clear-cut opening.
Gary Neville had time and space to the right of the Villa box to pick out the run of Park but he failed to make proper contact with his shot which curled wide of the far post.
On-loan Villa keeper Gabor Kiraly clung onto a low angled drive from Evra and then held onto Ronaldo's header which flew straight at him from Giggs' corner.
Darren Fletcher would have been disappointed not to have done better after racing onto a pass from Ronaldo and he stabbed the ball past the far post.
Giggs then led a break-out from defence by United before finding Ronaldo who turned past Hughes only to send his shot across the face of goal.
United were not to be denied and after 59 minutes Ronaldo broke the deadlock. He picked the ball up in his own half and was allowed to advance almost unchallenged to the edge of the Villa box.
His first shot was blocked by Gary Cahill but the rebound fell straight into the path of Ronaldo who crashed a unstoppable drive inside Kiraly's near post.
Ronaldo was now in irresistible form and more trickery set up a chance for Giggs whose goal-bound shot was blocked by Cahill.
But after 64 minutes a spectacular strike from Scholes looked to have wrapped up the points for United.
Giggs' corner was headed out by McCann but Scholes took aim from 25 yards out and volleyed a superb drive past Kiraly via the underside of the bar.
Ferguson brought on Wayne Rooney for Park and he immediately set up a chance for Ronaldo whose shot was parried by Kiraly.
The bookings started to mount up with McCann, Sutton and Scholes all yellow-carded in quick succession.
Ronaldo finished it off four minutes from time when he turned home Gary Neville's low cross.
Fergie: Mourinho got it wrong
Sir Alex Ferguson has called upon Chelsea manager Jose Mourinho to apologise
for the second time in 72 hours after Manchester United ensured they would be
top of the Barclays Premiership at Christmas.
Mourinho was forced to backtrack in midweek over his comments about the antics
of Everton striker Andrew Johnson.
Now Ferguson believes Mourinho should say sorry again after failing to live up
to his claims that Chelsea would be at the head of the table on December 25.
Two goals from Cristiano Ronaldo and a wonderful strike from Paul Scholes
today ensured United earned a comfortable 3-0 victory at Aston Villa.
Ferguson said: 'Perhaps it shows that we shouldn't believe Jose Mourinho. He
said Chelsea would be top at Christmas and they are not.
'He has to apologise after lying about an Everton player this week. Perhaps
he should be apologising again.'
Ferguson was pleased with the form of his side after the shock setback at West
Ham, and in particular Ronaldo - who tormented the Villa defence.
The Scot believes the Portuguese winger is 'as good as anyone in the
country' in his current form and he now has eight league goals to his credit.
Ferguson said: 'It is a big result after last week's disappointment when we
controlled the game, we should have won. The nature of football is that those
things happen.
'A new manager comes in (Alan Curbishley) and it is almost like fate at what
happens.
'But today the players got to grips with the game, played some great football
and we've also great determination because Villa are a handful.
'There wasn't much in it in the first half but after the break we turned it
around and Ronaldo was unbelievable.
'He is in great form. He shows great courage and strength and he was a
revelation today. He is as good as anyone in the country.
'He has got eight goals now and he could get us 15 this season. He is capable
of doing that.'
Ferguson left Wayne Rooney out of his starting line-up because of a midweek
family bereavement which meant him having two days off but he was hardly missed
as United strolled to victory.
Ferguson is also optimistic that midfielder Michael Carrick will be available
to play next week against Reading next weekend after being unavailable because
of an ankle injury.
The United chief explained: 'Michael did some light training yesterday and
reports that he will be out for a month are nonsense. He will be ready for
Reading.'
Villa, in contrast, have now gone seven games without a win and manager Martin
O'Neill felt that the first goal from Ronaldo early in the second half was the
turning point.
He said: ' We played well up until the first goal. We took the game to United
and I thought we were giving as good as we were getting. But it was
disappointing to lose the first goal in the fashion we did.
'We were attacking in their half, lost possession and Ronaldo runs a fair
distance and scores at the second attempt.
'We lost a bit of shape after that. They then scored a terrific second goal
through Scholes and we were chasing the game from then on.
'But we were up against a team that will be challenging very strongly for the
Championship.
'I have the utmost respect and admiration for Sir Alex Ferguson. He is
putting another team together who can challenge strongly.
'Eventually Manchester United beat us quite well but I'm not so sure the
scoreline tells the whole story.
'They are a class side which we will hope to aspire to one day - but that is
some distance off.'
Aston Villa 0 - 3 Manchester United
