Golovnina, 34, passed out at her office in the Pakistani capital, according to a statement from Reuters. Medical responders were unable to save her.
The cause of death is being investigated, police official Mohammad Yaqoob said.
"Maria was a superb journalist with a long and varied career at Reuters," the news agency said.
She joined the company in 2001 as a foreign correspondent in a number of places, including London, Singapore, Moscow, Afghanistan and Iraq. She had been bureau chief for Afghanistan and Pakistan since 2013.