Bradley found himself embroiled in controversy after his 2010 arrest stemming from an argument with his wife, Fumiko Bradley. Adam Bradley was accused of intentionally slamming a door on his wife's hands.
Later that year, a jury found him guilty of attempted assault and harassment.
But Bradley's defense was barred from calling witnesses -- including a police detective -- who would have testified that Fumiko Bradley told them her injury was accidental, not intentional.
"The right to present a defense constitutes 'a fundamental element of due process of law,' " State Supreme Court justices wrote in their decision.
The original trial judge "improperly precluded the defendant from adducing testimony which showed that his wife told others that the bedroom door was accidentally closed on her hand," the justices concluded.
"We are reviewing the decision and will make a determination on how we will proceed," Lucian Chalfen, spokesman for the Westchester County district attorney's office, told News12.
"Bradley is pleased about the ruling," said Eddie Still, his appellate attorney. "He believes the outcome will be different under a new trial."
However, the overturned convictions do not end the former mayor's legal troubles. He still faces a criminal contempt charge for allegedly breaking a court order not to contact his ex-wife.
Fumiko Bradley was "surprised" and "full of questions about what happens next" when she was told the convictions were overturned, according to her attorney, Neal Comer of White Plains.
If prosecutors choose to retry the case, Comer said, Fumiko Bradley would be called as a witness just as she was the first time around. Fumiko Bradley still maintains her husband abused her, Comer said, and believed the evidence against her ex-husband was strong.
The couple had two daughters together, and an order of protection prohibits Bradley from contacting his ex-wife.
"I think her concern, really, is not to have her children bothered," Comer told News12.
Bradley is due back in court Nov. 1.