The Holy Family School in Cootehill has closed temporarily to stop the further spread of Covid-19.
The decision was taken after a number of confirmed cases and in the interest of the health and wellbeing of all pupils and staff.
In a letter sent to parents, the Board of Management said eight cases of the virus have been identified recently, with three classes and two taxis or buses have been closed as a result.
It continues that three cases are suspected of being onward transmission at school, with public health advice being followed in all instances.
Having children come from across Cavan and Monaghan, how they travel to school and the large staff are all being considered as contributing factors to the spread of Covid-19.
As a result of this, and given that some staff have had to self-isolate, the Board of Management at the school said it had a duty of care to protect everyone's health so has decided to close the school until November 2nd.
The management says its thoughts and best wishes are with all those affected, and they look forward to reopening again at the start of next month.