On the 8th December 1868 the Sisters of Mercy at the invitation of Archdeacon O’Regan arrived in Kanturk and immediately became involved in the education of girls. In 1895 they set up the “Pension School” and in 1930 the school was henceforth known as Scoil Mhuire.
In 1933 girls presented for the Intermediate Certificate Examination and accommodation was gradually developed in the following decades on the Convent Avenue.
In 1978 the local lay Boys Catholic School closed and its staff and students moved to Scoil Mhuire thus making it a co-educational Voluntary Secondary School.
In 1987 a new block incorporating specialist rooms was built on the Greenfield Road and classes moved daily between the new block and the older buildings on the Convent Avenue.
In 2001 general classrooms were added close to the new block and since 2003 the older building on the Convent Avenue is no longer in use.
In 2005 the school gym was refurbished.
In 2006-7 Scoil Mhuire was transferred from Mercy Trusteeship (Southern Province) to CEIST (Catholic Education, An Irish Schools Trust).
In 2008 refurbishment included a small new extension to accommodate a new Technology Room and facilities for Design & Communication Graphics.
Since 2009 blackboards in classrooms were replaced with laptops, data projectors and interactive whiteboards.
In 2010 work was carried out in refurbishing the school gym. A fully equipped exercise room was added to the existing facilities. A lecture / Demonstration Room was created within the main school building which now accommodates over 60 people in tiered seating.
Summer 2012 saw the installation of a gas proving system. In 2013 a dust extraction system was completed in the woodwork department.
In 2014 the heating system was upgraded and the boilers replaced. A state of the art wireless computer network was installed at the end of the year.
Students starting in September 2015 begin to use ipads and eBooks in the classroom.