The information was shared with parents in a letter sent by the district’s chief superintendent, Bryan Szumlas, on Thursday.
In the letter, Szumlas said the names of the students and the schools they attend will not be released so as to protect their privacy.
“The principals of these schools will contact the community with an update from Alberta Health Services (AHS) and letters will be sent home,” Szumlas said.
He added that in all three cases, the school buildings have been declared safe by AHS and remain open to staff.
Classes at K-12 schools and licensed child-care programs in the province were cancelled until further notice on Sunday, March 15.
As of Thursday, AHS said there were 146 confirmed cases of COVID-19 in the province.