Barry netted twice and had a hand in the other two goals scored by Gabby Agbonlahor and substitute Marlon Harewood.
Following five games without a win, Villa bounced back to form and in the process slaughtered a very poor and demoralised Bolton side.
It was also something of a landmark for Villa as it is the first time in 20 games that Scott Carson has kept a clean sheet.
Villa coasted to their success, but for a long period in the first half they made hard work of their task against an indifferent Trotters outfit.
Bolton, devoid of confidence, did little to enhance their survival prospects. They lack confidence both in midfield and attack. As a result they were rarely in contention.
Their best chance came early in the match when Olof Mellberg turned the ball back into the path of Heidar Helguson, who fired tamely wide.
It proved an expensive miss as a couple of minutes later Villa stormed into the lead. Ashley Young, who had a much better game than of late, produced a cross from the left which Barry headed home from the edge of the six-yard box.
This was Barry's first goal of the season from open play and it opened up the way for Villa to secure a comfortable victory.
The vital turning point occurred eleven minutes into the second half when Barry whipped over a left-wing cross which Agbonlahor hit first-time past Ali Al-Habsi for his first goal in 13 games.
It was a huge relief for the young striker who has been trying desperately hard to end his barren spell.
The goal also signalled the end of Bolton's fight to survive. Al-Habsi kept out a Nigel Reo-Coker effort, but it was no avail as Young created the third goal when his cross cannoned away into the path of Barry, who whipped a left-footed shot into the net.
There was simply no response from Bolton. El-Hadji Diouf was misfiring in midfield and as a result there was no service for the front men.
Bolton were later sliced wide open when Barry swung over a free-kick from the right and the unmarked Harewood, who had taken over from out-of-form John Carew, was given a free header to notch Villa's fourth goal seven minutes before time.