Cathedral School was a private, Roman Catholic school in Portland, Maine. Cathedral School was founded by Sisters of Notre Dame de Namur in 1864. The school offered classes from kindergarten to 8th grade. It was the "mother school" of Maine's parochial school system. Shortly after temporarily housing what was formerly known as West School from 2012-2013, the building became home to Portland Adult Education, an adult education program committed to helping adults take the HiSET test, a GED equivalent, and, in certain circumstances, earn a high school diploma.