It follows fellow Toronto-headquartered Kinross Gold closing its head office last week for the same reason.
Iamgold said on Saturday its employee had last been at its office in Toronto, Canada, on March 6 and was now in self-quarantine at home, in a stable condition.
It said the person had attended two private company events and the Northern Ontario Night at the Steam Whistle Brewery but had not been to PDAC 2020, where organisers last week confirmed an attendee had tested positive for COVID-19.
Iamgold said attendees at the company events had been notified.
"Toronto office employees have been asked to work from home until the end of the week, March 20, 2020, at which point the company will reassess," it said.
Authorities have introduced measures including school closures to prevent the spread of the virus in Ontario.
Meanwhile miner and commodities trader Glencore has temporarily closed its London, UK, offices due to coronavirus, Reuters reported.
A Glencore spokesman told the wire service the move came after one of the company's employees tested positive for coronavirus.