The Real Canadian Superstore will require most customers to wear a mask while shopping, starting Aug. 29.
The move is designed to help stop the spread of COVID-19.
The supermarket chain, which is owned by Loblaws Inc., operates dozens of grocery stores from B.C. to Ontario.
“Many municipalities across the country have made masks mandatory in indoor spaces, including our stores,” a Loblaws spokesperson said in an email.
“Experts also believe that wearing masks properly is one of the best ways to reduce the transmission of COVID-19.”
The company said that masks would not be mandatory for people who are unable to wear one for medical reasons.
A number of other major retailers, such as Walmart Canada, have already moved to make masks mandatory for shoppers.
Some Canadian jurisdictions have also made masks mandatory in public places. However, others, like British Columbia, have not.
Public health officials say wearing a mask can reduce the risk of transmitting COVID-19 to others by preventing the spread of infected droplets.
Mask wearing is still considered a secondary precaution, and less effective than physical distancing.