Normal school schedules have been replaced with special ceremonies
The 1916 Proclamation has been read out by students at around 4,000 schools around the country as the Tricolour was raised.
It was part of Proclamation Day - which saw every educational institute mark the significance of the Proclamation.
Normal school schedules were replaced with special ceremonies to mark the significance of the document in this 1916 centenary year.
The Proclamation of the Republic, also known as the 1916 Proclamation or Easter Proclamation, was a document issued by the Irish Volunteers and Irish Citizen Army during the Easter Rising.
It states: "We declare the right of the people of Ireland to the ownership of Ireland and to the unfettered control of Irish destinies, to be sovereign and indefeasible".
Following the raising of the Irish flag, the Proclamation was read by a student, past pupil or special guest of each school or institution.
This was followed by a sharing of each school's 'Proclamation for a New Generation' - which set out the vision and ideals of the generation of 2016.
Students then presented a selection of music, theatre and poetry, either specially commissioned, to which family and friends were invited to attend.
Meanwhile, the words of the Proclamation have gone around the globe with thanks to a project by Trinity College Dublin.
Ahead of Proclamation Day, the Irish Army visited schools to deliver the national flag to students.
Commandant Stephen MacEoin was among those visiting officers, and he spoke to Newstalk Breakfast earlier.