Mount St. Michael Secondary School is an all-girls voluntary secondary school, under the trusteeship of the Catholic Education an Irish Schools Trust (CEIST), on the outskirts of Claremorris in County Mayo, Ireland. Located on what was the estate of Denis Browne (local landlord), it was founded in 1906 and began as a 'Secondary Top' in 1924. It developed into a full secondary school in 1940. In 1987, a board of management was set up, comprising representatives of trustees, teachers and parents. In 1990 a lay principal was appointed.