He was born in the parish of Clondrohid, County Cork, and grew up speaking Munster Irish in the MuskerryGaeltacht. He was a descendant of the Carrignacurra branch of the Ó Laoghaire of the ancient Corcu Loígde. He attended St Patrick's College, Maynooth and was ordained a priest of the Roman Catholic Church in 1867. He became a parish priest in Castlelyons in 1891, and it was there that he wrote his most famous story,. It was serialised in the Gaelic Journal from 1894, and published in book form in 1904. The plot of the story concerns a deal that the shoemaker Séadna struck with "the Dark Man". Although the story is rooted in the folklore the writer heard from shanachies by the fire during his youth, it is also closely related to the German legend of Faust. It was first published as a serial in various Irish-language magazines. Apart from Séadna, Ua Laoghaoire wrote an autobiography called 's Irish Book Company. In addition, he translated some stories of medieval Gaelic literature into modern Irish, such as Eisirt and An Cleasaí, and translated an abridged version of Don Quixote into his local dialect of Irish. Peadar Ua Laoghaire became known for his support for caint na ndaoine, the real Irish of the people rather than any attempt to revive older forms of Irish. But he also drew careful distinctions between what he saw as good Irish and bad Irish, saying in chapter 5 of Mo Sgéal Féin,
Before I left Liscarrigane, I had never heard from anybody's mouth phrases such as "tá mé", "bhí mé", "bhí siad"; I always used to hear "táim", "bhíos", "bhíodar", etc. Little things! – but little things that come repeatedly into conversation. A taut mode of expression, as against one that is lax, makes for finish in speech; in the same manner, a lax mode of expression as against the taut, makes for speech that is deficient. Besides, the taut speech possesses a force and a vigour that cannot be contained in speech that is falling apart...The loose mode of expression is prominent in Gaelic today and English is nothing else. English has fallen apart completely.
Accordingly, he strongly promoted Cork Irish as what he saw as the best Irish for propagation among the Irish people. He died in Castlelyons at the age of 80.
Papers on Irish idiom : together with a translation into Irish of part of the first book of Euclid, by the late canon Peter O'Leary ; edited by Thomas F. O'Rahilly.
Cómhairle ár leasa, articles published in the "Leader"
Mo shlighe chun Dé : leabhar urnaighthe
An article listing 487 of Ua Laoghaire's articles and works was published in Celtica in 1954.
