1828 - A site for O'Connell Schools was bought and the foundation stone laid by Daniel O'Connell. The school opened in 1831 with 4 classrooms for 600 children. The first superior was Blessed Edmund Rice.

1914 O'Connell Schools feature in the opening lines of the short story 'Araby' in Dubliners by James Joyce: "North Richmond Street, being blind, was a quiet street except at the hour when the Christian Brothers' School set the boys free. An uninhabited house of two storeys stood at the blind end, detached from its neighbours in a square ground. The other houses of the street, conscious of decent lives within them, gazed at one another with brown imperturbable faces."

1925 - The Department of Education accepted OCS into the State system.

1931 - Playing fields in Clontarf were leased by the Christian Brothers.

1943 - Hall opened. Founding of the O'Connell Musical and Dramatic Society.

1953 - On the 31st August the current primary school building was opened.

1957 - Mr. Luke O'Brien began teaching in O'Connell Primary

1977 - In June of this year St. Canice's school closed and OCS was now the only senior boys school in the parish.

1978 - O'Connell's Schools celebrated their 150th Anniversary.

2003 - O'Connell's Schools celebrated their 175th Anniversary with a live radio broadcast from the secondary school by former pupil Pat Kenny.

2007 - Luke O'Brien continued to teach voluntarily in O'Connell Primary and marked his 50th year as a teacher here.

2011 - Opening of Ronnie Delany Arena ( all weather sports area )