In a news conference Thursday, District Attorney Seth Williams said Josey was charged with simple assault, a 2nd-degree misdemeanor, WPVI reports.
Josey's supporters said they will fight the charges, which they believe were brought about by political pressure.
"It's insane. This is a direct result of the headlines... He put his life on the line for his career, and he's being treated like a criminal," John McNesby, president of Fraternal Order of Police Lodge 5, the largest officers' union, told the Philadelphia Enquirer.
"We have a D.A. who's caving under pressure instead of standing up for what's right," McNesby said.
Josey was filmed striking Aida Guzman during the after-parade festivities.
Video of the incident was posted to YouTube and received more than 1 million views, sparking public outcry. Guzman's attorney, Enrique Latoison, told WPVI that he supports the charges.
"We agree with the charges. We believe that this was the right thing to do in this matter," Latoison said.
The officer was put on 30-day suspension with intent to dismiss, CBS Philadelphia reported.
Josey is a 19-year veteran of the force. His career included a 2010 commendation for shooting a would-be convenience store robber while off-duty, according to NBC Philadelphia.
More From WPVI: