The Royal Newfoundland Constabulary says a woman ignored orders to stay home after she arrived from outside the province, so they put her in a holding cell.
The 53-year-old woman was arrested in Corner Brook. She is facing a charge under the Public Health Protection and Promotion Act, which carries a maximum fine of $5,000.
Police CBC News Tuesday their primary goal was to educate people on the need to stay home and arrests would only come if someone refused to comply.
In this case, police said education wasn't enough.
"Medical officials have been loud and clear this virus could devastate our community," said RNC media relations officer James Cadigan. "If you put people at risk we will take every measure available to us."
The woman is slated to have a hearing Wednesday morning in a Corner Brook courtroom. She'll likely appear by video link.
Police were given the power to enforce public health measures when Health Minister John Haggie declared a public health emergency last week.
The provincial government also introduced an online form for citizens to alert authorities of people refusing to isolate themselves.
The province had received more than 450 reports as of Tuesday.