Mater Dei Institute of Education (Irish: Institiúid Oideachais Mater Dei) was a linked college of Dublin City University since 1999, located in Drumcondra, Dublin City, Ireland, near Croke Park, on the site of what was formerly Clonliffe College, the Roman Catholic Seminary for the Archdiocese of Dublin. The college was founded by Archbishop John Charles McQuaid in 1966 as an institute for the training and formation for teachers of religion in secondary schools in the Republic of Ireland. Clonliffe was also affiliated to the Angelicum in Rome that offered a three-year course leading to a diploma and a four-year course leading to a Masters; Fr. Joseph Carroll was its first president. The foundation of the college was a response to the challenges posed by the Second Vatican Council. It has a Roman Catholic ethos and currently has approximately 800 students.
The college closed in 2016 when it was fully incorporated into the DCU Institute of Education.
The college offered several undergraduate courses, primarily in secondary religious education and specializes with its postgraduate courses (including Doctorates) in religion, the humanities and education, and faith and culture as well as theology and philosophy in dialogue. In 1999 Mater Dei Institute of Education became a College of Dublin City University.
In 2002 it has established an Irish Studies Department and is offering a BA programme in Religious Studies and Irish Studies. The Institute sees this as a contribution to the understanding that is engendered by the Good Friday Agreement. The Institute also has links with colleges in Northern Ireland, France, Italy and the USA. Mater Dei partners with the Methodist Edgehill Theological College (Belfast) co-offering such as a BTh exploring faith together.
In 2008 the relationship linking Dublin City University with All Hallows, St. Patrick's College of Education, Drumcondra and Mater Dei Institute of Education was revised.
The Institute is engaged in the Erasmus student exchange programme with other colleges in Austria, Belgium, England, France, Germany, Greece, Italy, Malta, Portugal and Spain.