St. Mary's Hospital (Irish: Ospidéal Naomh Mhuire) was a psychiatric hospital in Castlebar, County Mayo, Ireland.

The hospital, which was designed by George Wilkinson opened as the Castlebar Asylum in 1866.

[1] Pádraig Flynn, Minister of State at the Department of Transport, officially opened a new Industrial Therapy Unit in May 1981.

[2] After the introduction of deinstitutionalisation in the late 1980s the hospital went into a period of decline[3][4] and closed in 2006.

[2] The building was converted for use as the Mayo Campus of the Galway-Mayo Institute of Technology in 1994.