Australia completed a remarkable turnaround after losing 4-0 in India and 3-0 in England last year, crushing the dispirited tourists with five dominant victories on home soil.
England reached the tea interval on 87 for three chasing a highly improbable 448 for victory and when four wickets fell in the first 11 balls after the break, their miserable tour was all but over.
Pacemen Ryan Harris (5-25), later named Man of the Match, and Man of the Series Mitchell Johnson (3-40) did the most damage as the hosts dismissed the tourists inside 35 overs.
Australia had already reclaimed the coveted urn after winning the Brisbane Test by 381 runs, the Adelaide match by 218 runs, in Perth by 150 runs and taking an eight wicket triumph in Melbourne.
A fifth thumping victory had always looked on the cards after Australia's pace attack tore through England's top order in the first hour of day two.
A similar collapse after tea on day three made it certain and the SCG, bathed in pink in honour of Glenn McGrath's breast cancer charity, rose to hail the Australians after Harris had ended England's resistance by dismissing Boyd Rankin.
"It's obviously a very special occasion. We couldn't have foreseen the 5-0 after the England series but I said then the work we were putting in was going to get rewards," a beaming Clarke said at the presentation ceremony.
"I think the bowlers have done a fantastic job. In my opinion we have the best attack in the world. I think they've earned that mantle."
Chris Rogers had earlier recorded his highest Test score with a knock of 119 to inflate Australia's lead before they were dismissed for 279 soon after lunch.
The tourists were always facing a monumental task given the highest successful fourth innings run chase at the Sydney Cricket Ground was the 288 Australia achieved to beat South Africa in 2005-06, and the start to their innings did not help.
In the second over, Alastair Cook's miserable tour continued when he prodded at a Johnson delivery and caught an edge which Brad Haddin scooped up behind the stumps.
The England skipper's seven runs gave him 246 at an average of 24.6 for the series, a poor return compared to the 766 runs at 127 he accumulated on his last trip to Australia in 2010-11.
"It's tough knowing you've played your five matches and lost them all badly," Cook said.
"We weren't good enough to turn it around. But you have to give credit to Michael and his team, they thoroughly deserved their victories."
Ian Bell, the difference between the two sides in England's 3-0 triumph in the first Ashes series of the year, faced 19 balls before he too headed back to the pavilion after cutting the ball straight to Dave Warner at gully off Harris.
England were now 37-2 and looking to their last experienced batsman, Kevin Pietersen, to give the innings some stability.
George Bailey put paid to those hopes when he took a brilliant catch after a Harris delivery had taken an inside edge and looped over his head off Pietersen's pad.
Michael Carberry had made 43 at tea but was gone without adding to his score in Johnson's first over after lunch with Gary Ballance following him three balls later - Johnson's 36th and 37th victims of the series.
Spinner Nathan Lyon took over for the next over and he dismissed Jonny Bairstow (0) and Scott Borthwick (4) to reduce the tourists to 95-7 in a matter of minutes after the interval.
Ben Stokes (32) and Stuart Broad (42) again provided England's stiffest resistance down the order but Harris bowled them both and then performed the coup de grace on Rankin.
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