Mandatory masks will be required to be worn by those in the ACT from midnight on public transport and in public indoor venues such as supermarkets, gyms and hospitality venues.
A 48-hour transition period is being put in place to allow businesses and residents to adapt to the new requirement.
The ACT has no local coronavirus cases or current exposure sites, but ACT Health said the measure is being adopted as “proactive measure”.
“The safety of our community is paramount, so we are bringing in this requirement as a proactive measure to support the strengthened travel restrictions we have in place.”
On Saturday, the ACT closed its border to anyone in the Greater Sydney region. Travel restrictions have also been imposed in parts of the Northern Territory, after awas announced to contain a COVID-19 outbreak.
From 4pm, ACT residents returning from the City of Darwin, City of Palmerston and Litchfield local government areas in the NT will be subject to stay-at-home orders.