In front of a delirious crowd at Perth's WACA ground, England's resistance came to an end after lunch on the last day as they were skittled out for 353, with a deficit of 150 runs.
The victory, which followed wins of 381 and 218 runs in Brisbane and Perth, gave Australia an unbeatable 3-0 lead in the five-match series and their first Ashes triumph in four attempts.
It capped a remarkable turnaround for Australia, who were not fancied going into the series just months after a 3-0 loss in England. They also suffered defeats in 2009 and 2010-2011. (Darren Lehmann behind Australia's Ashes turnaround)
"I don't really know what to say. We've got them back, I couldn't be happier," Clarke said of the Ashes. (I know how Cook feels, says Michael Clarke)
"Credit to the team for how they played: they were outstanding." (Australia's unique pitch tribute)
English rookie Ben Stokes, 22, frayed Australian nerves with a dogged 120, his maiden Test century, before he was caught brilliantly by Brad Haddin after lunch, triggering a clatter of England's last wickets.
Fittingly fast bowler Mitchell Johnson, whose destructive spells have played a large part in Australia's victory, took the decisive scalp when he had tail-ender James Anderson caught at short leg.
England captain Alastair Cook, who on Monday was out for the first golden duck of his career in his landmark 100th Test, admitted the heavy series defeat was painful.
"We have been out-skilled in all aspects, and it is hard to say that. They have been ruthless. It hurts," Cook said. (Hurts like hell, says Alastair Cook)
However, the pain may not be over for England as Clarke, now seeking a return to the world number one ranking for Australia, sets his immediate sights on a 5-0 whitewash.
"I am going to enjoy 3-0 for as long as I can tonight. I am going to enjoy this feeling, but I can guarantee you there won't be any complacency," he said.
"We will turn up (for the next Test) in Melbourne 100 percent ready to go and be doing everything we have done in the first three Test matches."
Set a record 504 to win, England went to lunch on the final day at 332-6 after losing just one wicket in the morning session, that of Matt Prior for 26.
Despite huge cracks on the parched WACA deck, and needing 172 more runs with only four wickets in hand, Stokes' rock-solid batting in just his second Test was tempting England to think the unthinkable.
However, Australia got the vital breakthrough when Stokes tried to sweep spinner Nathan Lyon (3-70) and got a thin bottom edge which was outstandingly held by wicketkeeper Haddin.
It was the end of a superb knock by Stokes, who showed up his more senior team-mates by staying at the crease for 257 minutes and facing 195 balls, hitting 18 fours and one six, in England's first century of the series.
Lyon then picked up Graeme Swann for four, caught at short leg, before Johnson had Tim Bresnan (12) brilliantly caught by the diving Chris Rogers at mid-off.
And the match was over when Johnson (4-78) claimed his 23rd wicket of the series, with Anderson popping up an easy catch to George Bailey.
England had resumed on their overnight score of 251-5, but New Zealand-born Stokes defied the Australian attack for the entire morning session, losing only Prior along the way. (Boycott slams 'selfish' Kevin Pietersen)
Stokes was temporarily denied a century when he drove Johnson straight and the ball deflected off the bowler's hand into umpire Marais Erasmus, costing him the two runs he needed to reach the milestone.
But he got a top edge to fine leg for a boundary from the next ball to notch his first Test century.
Not for the first time in the series, it was Johnson who delivered a dagger to English hearts by removing Prior in his third over with the second new ball, ending a 76-run partnership with Stokes.
Australia coach Darren Lehmann, who inherited a divided and misfiring team when he took over earlier this year, said the players had executed his plans to perfection.
"The way the players implemented plans, from batsman one to 11, was exceptional," Lehmann said.
"We've played some good cricket, but they (England) have had opportunities as well.
"I think (in the last series) in England we lost those key moments, here we've won them."