Media playback is not supported on this device
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".
The English Football Association has given its backing to Michel Platini's bid to become the next boss of Fifa.