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 in its Toronto office 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 20th, 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 (LSE: GLEN) has temporarily closed its London 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.
Nine new countries reported cases of COVID-19 in the past 24 hours, according to the World Health Organisation yesterday, with the number of confirmed cases at 153,517 globally and 5,735 deaths.
Iamgold shares touched a one-year low of C$2.60 on Friday while Glencore gained 6.7% to 135.68p but it remains near a 52-week low.
At Iamgold's close of $2.63, it is capitalised at $1.2 billion (US$0.9 billion) and Glencore is valued at £16.9 billion (US$20.8 billion).