The Federal Aviation Administration says the helicopter crashed into a wooded area on Friday afternoon while approaching Flying W Airport in Medford.
The pilot was also killed.
The crash happened hours before the duo was due to perform a concert at a resort that is also based at the airport.
“It is with great sadness that we confirm that Troy Gentry, half of the popular country duo Montgomery Gentry, was tragically killed in a helicopter crash which took place at approximately 1.00pm in Medford, New Jersey,” the band’s website said.
“The duo was scheduled to perform tonight at the Flying W Airport & Resort in Medford. Troy Gentry was 50 years old.”
Medford Township police chief Richard Meder told local media that police got a call about a helicopter that was “distressed”.
He said crews were able to remove the country star from the wreckage, but he died on the way to the hospital.
The pilot died at the scene and crews were working to remove his body, Meder said.
Gentry was born on 5 April 1967 in Lexington, Kentucky, where he met Eddie Montgomery and formed a group in 1999 based on their last names.
Montgomery Gentry had success on the country charts and country radio in the 2000s, scoring number one hits with Roll With Me, Back When I Knew It All, Lucky Man, Something to Be Proud Of and If You Ever Stop Loving Me.
The FAA and the National Transportation Safety Board are investigating the cause of the crash.