The Gunners top scorer struck with a stunning lob and a trademark curling shot after Emmanuel Adebayor headed them in front. Subs Robin van Persie and Abou Diaby made Villa suffer even more.
Henry will make a decision on his future before the start of the World Cup. Arsene Wenger and the Gunners fans are sweating on the outcome.
Henry says he must be fully focused first on the climax of Arsenal's season first. Perhaps, like Steven Gerrard at Liverpool last season, he is keeping his options to see how Arsenal fare in the Champions League.
After their win at Real Madrid, Arsenal lost 1-0 four days later at Blackburn. There was never any danger of a repeat hitch after their victory over Juventus.
It was a good day for the Gunners in the race for fourth place. They moved up to fifth, two points behind Tottenham with a game in hand and Spurs still have to visit Highbury. Arsenal are a point ahead of Blackburn (who play Wigan on Monday) and five clear of seventh-placed Bolton.
The Gunners' only concern - ahead of the Champions League quarter-final second leg in Turin - was the 15th-minute departure of Cesc Fabregas, who pulled up in pain after hitting a pass.
Meanwhile, the result increases the pressure on Villa manager David O'Leary, whose side have gone five games without a win.
The lack of experience among the Villa subs showed his squad's lack of depth. How the missed the influence of their injured defensive organiser Olof Mellberg as Arsenal teased and probed.
Jose Antonio Reyes cut inside on to Philippe Senderos' pass and found Henry, but Robert Pires slipped as he ran on to the flick.
Liam Ridgewell then made a last ditch-tackle to deny Henry as he chased Emmanuel Eboue's through ball, before Pires and Reyes stretched the Villa defence almost at will.
But Kevin Phillips could have shocked the Gunners in the 18th minute when he collected Luke Moore's flick but he chipped wide from 15 yards.
Adebayor gave Arsenal the lead a minute later. Henry's shot on the turn beat keeper Thomas Sorensen. Ridgewell cleared off the line, only for Adebayor to nod home the loose ball.
Henry added a majestic second in the 25th minute, instantly controlling Reyes' long pass and coolly lobbing Sorensen. He made the very difficult look incredibly easy.
Villa's midfield could fashion little. Arsenal, by contrast, still made chances despite dropping into cruise mode with Juventus in mind.
Henry, linking with Adebayor, played in Eboue whose shot squirmed under Sorensen but trickled wide.
The trio combined again for the third, a minute after the interval. Adebayor delicately touched Eboue's pass to Henry who unleashed a typical curler that left Sorensen stranded.
Sorensen saved Senderos' header. Reyes fired wide and the Villa keeper tipped away Adebayor's header as Arsenal contined to press.
Moore's 62nd-minute shot forced Jens Lehmann to save with his feet. It was a rare moment.
Sorensen held Adebayor's shot, before van Persie added the fourth, running onto Pires' pass to beat Sorensen from a tight angle. Van Persie had replaced Henry, taking a break before the task against Juventus.
Diaby completed the rout, crashing home Adebayor's pass to finish a move that he and Pires had begun in their own half.
Wilfred Bouma failed by inches to connect with a knock-down at a late corner, so Villa were denied even a consolation. It is now 16 matches since they last beat the Gunners.