The present library building was completed in 1830 and houses some 100,000 volumes including those which formed the original collection, purchased in 1787. 

While in the past the Society sought to create a comprehensive general library, the emphasis in recent years has been on developing the legal collection. The legal collection contains all of the Irish and most of the English textbooks along with statutes, reports of cases, digests and legal periodicals. European, Commonwealth and American Law are well represented and amongst the older legal material are fine collections of trials, Irish appeals to the House of Lords, nominate reports, Roman law and canon law. 

The general collection contains works on art, history, the classics, literature, biography and numerous other subjects. Of particular note are the holdings of incunabula, parliamentary papers, Encumbered Estates Court Rentals, pamphlets and manuscripts.