The Calgary Catholic School District says masks will need to be worn by kindergarten to Grade 12 students and staff at the beginning of the school year in September.
The CCSD said the decision was made after considering the increase of active COVID-19 cases in Alberta, and particularly in Calgary.
It added the decision was made given vaccination rates for youth aged 12 to 19, and the fact that younger students do not yet have a vaccine available to them.
"We have the responsibility to ensure that each student and staff member is provided with a welcoming, caring, respectful and safe learning environment," said superintendent Bryan Szumlas in a statement.
The decision followed a similar move by the Calgary Board of Education, which announced Wednesday that it was taking a similar route forward.
The CBE's decision will be reviewed before the end of September, and it said it will consider any further direction from the province's chief medical officer of health, Alberta Education and active case counts in the Calgary area.
"We all play a role to ensure our return to school is as safe as possible and that we minimize the spread of COVID-19 in our schools and workplaces. The CBE has and will continue to encourage all eligible employees to get vaccinated," chief superintendent Christopher Usih said in an email sent to parents on Wednesday.
Other health measures at the CCSD will include:
Requiring students and staff to use a daily checklist to identify if they should attend school or stay home.
Requiring students to sanitize or hand wash as they enter the building and as they enter and exit classrooms.
Implementing classroom cohorts where possible.
Sanitizing on a regular basis.
Like the CBE, the CCSD said schools will no longer inform close contacts of positive cases, at the direction of the chief medical officer of health.
Registration for online learning through St. Isidore School and Anne High School remains an option for families. The deadline to register is Sept. 2.