Saint Patrick’s Day was declared a public holiday in Ireland in 1903.
The change came through the Bank Holiday (Ireland) Act 1903, introduced in the Parliament of the United Kingdom by James O’Mara, an Irish Parliamentary Party MP. At the time, all of Ireland was part of the United Kingdom, so the holiday’s legal status was established under British legislation.
The date, 17 March, was already associated with Patrick’s feast day and had been observed by Irish communities for centuries. Making it a public holiday gave the observance official civic status, distinct from its earlier religious importance. The day had also become a prominent expression of Irish identity, especially among people campaigning for cultural and political recognition.
A common mix-up is confusing 1903 with later milestones. The first official state-sponsored Saint Patrick’s Day parade in Dublin did not take place until 1931, while the first parade in Ireland was held in Waterford in 1903. The holiday is now associated with parades, shamrocks, Irish music and the global Irish diaspora, but its legal foundation dates to the 1903 act.