Hardy was officially charged with assault on a female and communicating threats.
WSOC-TV in Charlotte first was told of the arrest by the Charlotte-Mecklenburg Police Department.
"We are very disappointed to learn of the allegations involving Greg and are concerned for all parties as we continue to investigate," the Panthers said in a statement.
Hardy will spend Tuesday night in jail and appear in front of a judge at 9 a.m. ET Wednesday, court officials told ESPN.com.
According to the police report, at 4:18 a.m. on Tuesday, officers responded to a domestic violence assault call for service in the 100 block of North Tryon Street. Upon arrival they spoke to the woman, who told them she had been physically assaulted and threatened by Hardy. She also said she and Hardy have been in a relationship since September 2013.
Hardy, who also goes by his alter persona "The Kraken,'' led the Panthers in sacks this past season with 15. He was given the franchise tag during the offseason, guaranteeing him $13.1 million in 2014.
Carolina general manager Dave Gettleman has said repeatedly he hopes to sign the 2010 sixth-round pick to a long-term contract.