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Platini wants to restore the image of world football's governing body in the wake of serious corruption allegations.
"We want a reform candidate," said FA chairman Greg Dyke. "We believe he will reform Fifa in the way that reform is needed."
Sepp Blatter has already announced he will quit as Fifa president, with an election set for 26 February.
Frenchman Platini, president of European football governing body Uefa, is likely to face a number of challengers, among them Prince Ali Bin al-Hussein of Jordan and Liberian FA president Musa Bility.
Dyke added: "We understand there will be a number of candidates, which should result in a strong and healthy debate.
"However, we should not underestimate how challenging it will be for anyone to lead an organisation that has been so tainted. The whole structure of Fifa must be reviewed and fundamentally changed."
Platini has found himself at odds with the FA over Qatar's successful bid to host the 2022 World Cup.
The 60-year-old championed the Gulf nation despite concerns over its human rights record and severe summer temperatures.
But Dyke attempted to play down any differences for the time being, saying: "Mr Platini has always made it very clear that he voted for Qatar.
"If all the other people who voted for Qatar had been quite as transparent it would have been more helpful."
Not everyone shares the FA's confidence in Platini, a former France international who won the coveted Ballon d'Or three times.
Just hours after confirming his candidacy on Wednesday, he was criticised by two potential presidential rivals.
Prince Ali and Bility both claim Platini would be a bad choice as a successor.
Prince Ali, who stood against Blatter in the last presidential election, said that "football's fans and players deserve better".
A member of the Jordanian royal family, he added that Fifa needed a "new, independent leadership, untainted by the practices of the past".
Bility agreed, telling the BBC's World Football programme that Platini would bring "chaos", "more division" and "more problems".

Jay Bell's actions on 26 July 2013 caused the infant to suffer brain bleeding, retinal haemorrhages and a broken rib and ankle.
As a result of the brain injury, the child suffers from cerebral palsy and is registered blind.
Bell, 23, from Mayfield in Dalkeith, last month admitted to two charges.
He pleaded guilty to culpable and reckless conduct towards the child to his severe injury, permanent impairment and to the danger of his life and a second charge of wilfully neglecting the baby and failing to seek medical attention for him.
Passing sentence at the High Court in Edinburgh on Thursday, judge Paul Arthurson QC described the offences as "extremely serious".
The baby did not receive hospital treatment for about two weeks and Bell took about five months to reveal what had happened to the child when he was in his care.
The court heard Bell threw the child in the air repeatedly but the baby hit his head on the wall, then hit a Moses basket and fell on the floor.
Bell then picked him up and shook him repeatedly until he began to cry.
The court heard the child was eventually admitted to the Royal Hospital for Sick Children on 10 August 2013 and it took Bell until December that year to disclose fully what had happened to the baby.
Had the child gone to hospital straight after suffering the brain injury, medical intervention may have limited the impact of that injury, the judge said.
Prosecutors accepted that while Bell's conduct was culpable and reckless, it lacked the "wicked intent" of an assault.
Defence counsel John Keenan said Bell never set out to harm the child.
He has shown remorse and is having "extreme difficulty" coming to terms with what happened, the solicitor advocate said.
The judge said Bell's culpability was at the lower end of the scale.
"I accept that while the consequences for the child were truly catastrophic, these were not intended by you," he told Bell.
"Nevertheless, taking into account your position of care and trust and the extreme vulnerability of the child, the only appropriate disposal for the offences is a substantial custodial one."
The English Football Association has given its backing to Michel Platini's bid to become the next boss of Fifa.
[NEXT_CONCEPT]
A Midlothian man who threw a baby in the air and shook him, causing him to suffer "catastrophic" injuries, has been jailed for four years.