Healy struck a stunning 170 from 138 balls at the Hagley Oval in Christchurch as the Australians added to their T20 World Cup and Ashes successes to reaffirm their status as a world powerhouse.
Rachael Haynes also posted 68 and a 160-run partnership with Healy helped Australia reach 356-5 as they made England pay for deciding to field first in perfect batting conditions.
Nat Sciver came away with credit for an unbeaten score of 148 when England were finally dismissed for a total of 285, with spinners Alana King and Jess Jonassen both taking three wickets apiece.
Victory over England saw Australia crowned world champions for the seventh time as they posted a perfect record of nine wins from nine games.
Australia captain Meg Lanning Sky Sports: "We have been extremely consistent over a long period of time. It's been a massive build-up to this tournament, it's been a long time coming, and to come out and perform so well, throughout the whole tournament, is pretty amazing. I think we deserved the victory today."
On Healy's stunning knock, Lanning said: "It was incredible. Some of those shots were ridiculous.
"Just to put the bowlers under pressure was important and she set the base really nicely to explode at the back end."
A dejected England captain Heather Knight conceded Australia's firepower had given her team too much ground to make up.
She said: "It was probably a 50-50 decision at the toss, whether to bat or bowl first, but credit to Australia, to bring that sort of performance in a World Cup final was outstanding."
On wicket-keeper Healy's incredible innings, she added: "Alyssa's innings was remarkable - not a pleasure to watch but one of the best innings I've seen live."
Knight said her team-mates had shown resolve and powers of recovery to reach the final given that they lost their opening three games of the tournament but admitted chasing Australia's huge score was a bridge too far.
She said: "I guess we didn't quite find an answer. It was an amazing wicket, really hard to defend. If we'd kept them just above 300 - which was about par - we'd have had a good chance of chasing it down."