This is an edited version of my post on Alsatia, listing the various freely available editions of Irish legislation before the Act of Union in 1800.
There were three collections of the Irish statutes published in the eighteenth century. The first was the Acts and Statutes Made in a Parliament begun in Dublin, published intermittently up to the 1760s. A handful of these are available through Google Books. As it is printed in gothic type, its utility for OCRing, or even just reading, is limited. The second was The Statutes at Large, Passed in the Parliaments Held in Ireland, collecting the acts up to 1761 and was edited by James Goddard Butler. This series was then continued up to 1800. All the volumes are available, the majority through Google, but some only through the Oireachtas archive, whose online catalogue is wretchedly misconfigured, a useability nightmare, limited of bandwidth, and full of erroneous metadata: in short utterly broken. (To locate these volumes, the best thing to do is click this link for a search on the title, and then click on the header of the entry, not the deceptive link to the pdf.) The third set was published from 1794 to 1800, entitled Statutes Passed in the Parliaments Held in Ireland, of which all volumes are available via Google. However, it doesn’t contain the text of acts previously repealed. I have OCRd these last two series, and the texts, currently undergoing correction, can be downloaded from Github.
Update 3 May 2023: The Oireachtas archive is, at least in part, now available through Jstor, for free. Search for Irish statutes.
In the early twentieth century the Irish Record Office commenced publishing a five volume series of early statutes, with the first three volumes published by 1914, and now freely available online. The fourth volume was published in 1939, and the last in 2002; thanks to the Virtual Treasury the complete set is available online..
Other sources: There is a very little pre-1800 Irish legislation on the UK legislation portal, and similarly a little at the Irish Statute Book. The Irish Legislation Database has detailed information concerning each act, but not their texts. A useful website from the University of Minnesota covers the anti-catholic Penal Laws. Wikipedia has two pages listing the acts, up to 1700 and from 1700 to 1800.
Irish Record Office Series of Early Statutes
- Volume 1: King John to Henry V. Google. Internet Archive. Virtual Treasury.
- Volume 2: Henry VI. Google. Virtual Treasury.
- Volume 3: Edward IV, first to twelfth years. Google. Virtual Treasury.
- Volume 4: Edward IV, twelfth and thirteenth to twenty-first and twenty-second years. Virtual Treasury.
- Volume 5: Richard III to Henry VIII. Google (search only). Virtual Treasury.
Statutes Passed in the Parliaments Held in Ireland
- Volume 1: 1310-1662
- Volume 2: 1665-1712
- Volume 3: 1715-1733
- Volume 4: 1735-1759
- Volume 5: 1761-1772
- Volume 6: 1773-1780
- Volume 7: 1781-1785
- Volume 8: 1786
- Volume 9: 1789-1793
- Volume 10: 1794-1796
- Volume 11: 1797-1798
- Volume 12: 1799-1800
The Statutes at Large, Passed in the Parliaments Held in Ireland
- Volume 1: 1310-1612
- Volume 2: 1634-1662 (Oireachtas.ie pdf)
- Volume 3: 1665-1698 (Oireachtas.ie pdf)
- Volume 4: 1703-1719
- Volume 5: 1721-1731
- Volume 6: 1733-1747
- Volume 7: 1749-1761
- Volume 8: Indexes
- Volume 9: 1763-1767
- Volume 10: 1769-1776
- Volume 11: 1777-1780
- Volume 12: 1781-1784 (Oireachtas.ie pdf)
- Volume 13: 1785-1786 (Oireachtas.ie pdf)
- Volume 14: 1787-1789
- Volume 15: 1790-1791 (Hathi Trust)
- Volume 16: 1792-1793
- Volume 17: 1794-1796 (Oireachtas.ie pdf)
- Volume 18: 1797-1798
- Volume 19: 1799
- Volume 20: 1800
Acts and Statutes Made in a Parliament begun in Dublin