It's the sixth fatality reported by the South Africa-based miner this year.
Harmony said an employee was fatally injured following a fall of ground incident at the mine in the North West province.
The deep underground mine, acquired in 2018, had produced 211,938 ounces in FY20 - less than a year earlier due to COVID-19 and seismic activity.
Authorities and organised labour were informed and an investigation into the incident was currently underway, Harmony said on Friday.
"Operations in the affected section have been suspended in the interim," it said.
Management extended condolences to the deceased employee's family, friends and colleagues.
"The company continues to strive towards its goal of zero loss of life and will ensure that the necessary support is provided to the family in dealing with this tragedy," CEO Peter Steenkamp said.
Harmony is due to present its FY21 results on August 31.
