Angel Gahona was reporting live on unrest in the central American country when he was shot dead.
At least 25 others have been killed in the last few days amid demonstrations against increased taxes, according to human rights groups.
Mr Gahona was in the entrance to the city hall of the southeastern city of Bluefields on Saturday when he was hit by gunfire.
The reporter was describing damage to a cash machine he was videoing with his phone as a cameraman filmed behind him when a shot rang out.
Suddenly, he falls to the ground as others around him are heard screaming his name.
He was taken to hospital with a serious head wound but another Bluefields reporter, Ileana Lacayo, said he died en route.
Police have been unable to identify who fired the shot, with officers and other groups fighting the protesters the only ones believed to have been armed.
Dozens of shops in the capital Managua have been looted in the last 24 hours amid the five-day long violence which is over government social security reforms.
The demonstrations erupted in response to President Daniel Ortega’s effort to shore up the troubled social security system with a mix of reduced benefits and increased taxes.
State-controlled media blamed protesters for the looting, while critics claimed that it was being allowed to pressure the business sector to force the government to end the harsh crackdown.
Mr Ortega said on Saturday he would negotiate on the reforms, but only with business leaders.
He also tried to justify the tough response to the protests, accusing the demonstrators of being manipulated by politicians and gangsters.
“What is happening in our country has no name. The kids do not even know the party that is manipulating them,” Mr Ortega said.
“Gang members are being brought into the kids’ protests and are criminalising the protests. That is why they are put at risk,” he added.
His remarks appeared to backfire as soon after he finished speaking thousands of people spilled back into the streets in seven cities.
At least two more protest marches have been planned in Managua on Sunday.
Marlin Sierra, director of human rights organization CENIDH, said most of the dead were aged between 15 and 34.
The government put the number of dead at “almost 10” by late on Friday.
Also on Sunday, Pope Francis called for an end to the violence.
Mr Ortega, a former Marxist guerrilla and Cold War antagonist of the United States, has presided over a period of stable growth with a blend of socialist policies and capitalism.
But critics accuse the President and his wife, Vice President Rosario Murillo, of trying to establish a family dictatorship.
The US condemned the police violence on Sunday and urged the government to allow journalists to go about their work without risk.
Meanwhile, the North American football governing body, CONCACAF, cancelled the remainder of its Women’s Under-17 Championship being staged in the country due to safety concerns.