St John's College is a secondary school in Ballyfermot, Dublin, Ireland. The school is run by the De La Salle Christian Brothers. St John's College is fully funded by the Department of Education. The current Principal is Ann Marie Leonard, since 2007 and the current Deputy Principal is Adrienne Murphy, since 2008.

This school offers four class levels. 1st year, 2nd year and third year which have 4 classes. Each class has an average number of 15–23 students. St John's offers the transition year all students from 3rd go into different classes for different subjects. In 5th year, students are divided into two-year programmes called Leaving Certificate, Leaving Certificate Applied and Leaving Certificate Vocational Programme. Students have a choice to pick one of these programs which continue into the 6th year.

In December, students participate in the Christmas Examinations. In March, 3 and 6 year students sit the Pre-Junior Certificate Examinations or the Pre-Leaving Certificate Examinations. 1st, 2nd and 5th year students sit the Summer Examinations in late May and early June. Junior Certificate Examinations and Leaving Certificate Examinations are held on 10 June.

This college was founded in 1956 by the Institute of the Brothers of the Christian Schools and is managed by the Institute as a state-funded institution. The college is based on the principles of Jean-Baptiste de La Salle, a pioneer in modern education who founded the Institute of the Brothers of the Christian Schools.^[1] Commonly known as the De La Salle Brothers in Britain, Ireland, Australasia and Asia, they are known in the United States and Canada as the Christian Brothers. They are sometimes confused with a similar congregation founded in Ireland by Edmund Ignatius Rice commonly known as the Irish Christian Brothers.

This section does not cite any sources. (March 2019)

• Joe Duffy, broadcaster. The school featured in his Joe.
• Willo Flood
• Brian Shelley