Three Court of Appeal judges gave their decision on Thursday following appeal proceedings last month.
The former Sheffield United striker and Welsh international was present at the London court for the hearing with girlfriend Natasha Massey by his side.
The court ruled that the grounds for the appeal cannot be reported at this stage.
Lady Justice Hallett, Mr Justice Flaux and Sir David Maddison heard submissions over two days from Kieran Vaughan QC, for Evans, and from Eleanor Laws QC, for the Crown.
Announcing the court's decision, Lady Justice Hallett, said the judges had heard "fresh evidence" during the appeal hearing on March 22 and 23.
She said: "In summary, we have concluded that we must allow the appeal and that it is in the interests of justice to order a retrial."
A fresh indictment will now be served and Evans will be re-arraigned on the new charge within two months.
After the ruling Evans left the Royal Courts of Justice hand in hand with his girlfriend.
His conviction was referred to the Court of Appeal for review by the Criminal Cases Review Commission (CCRC), which investigates possible miscarriages of justice.
The CCRC announced last October that new evidence had emerged in the case.
In a hearing on March 22, Evans sat in the packed courtroom with girlfriend Natasha Massey by his side.
An order made by the Court of Appeal judges prevented reporting of the details of the legal argument.
Evans was released from prison in 2014 after serving half of his five-year sentence.
The referral to appeal judges followed a 10-month investigation by the commission.
When the decision was announced, CCRC chair Richard Foster said: "The decision of the commission is not a judgment on guilt or innocence in relation to Ched Evans, nor is it a judgment about the honesty or integrity of the victim or any other person involved in the case.
"Our role is to consider applications to see if, in our judgment, there is any basis on which to ask the court to hear a fresh appeal - that is our statutory responsibility.
"In this case we have identified new material which was not considered by the jury at trial and which, in our view, might have assisted the defence.
"In those circumstances, it is right and proper for the matter to be before the court so that they can decide whether or not the new information should affect the verdict in this case."
Evans previously lost his case at the Court of Appeal in 2012.