Cathal Ó Searcaigh (born 12 July 1956), is a modern Irish language poet. His work has been widely translated, anthologised and studied. "His confident internationalism", according to Theo Dorgan, has channeled "new modes, new possibilities, into the writing of Irish language poetry in our time".
 Since 1975, he has produced poetry, plays, and travelogues. His early poetry deals with place, tongue and tradition, with his late work showing a broader scope. His work includes homoerotic love poems. Jody Allen Randolph remarks "his breaking down of stereotypes and new deployment of gendered themes opened a new space in which to consider alternate sexualities within a contemporary Irish context."
 The critic John McDonagh argues that "Ó Searcaigh occupies many of the spaces that stand in opposition to the traditionally dominant markers of Irish identity". In his anthology, McDonagh goes on to say "Ó Searcaigh's homoerotic poems are explicit, relishing in a sensuality that for many years rarely found explicit expression in Irish literature."
 Cathal Ó Searcaigh was born and reared on a small hill-farm at the foot of Mount Errigal (An tEaragal) in the Donegal Gaeltacht. He was educated locally at Caiseal na gCorr National School and then at Gortahork Vocational College (Gairmscoil Ghort a' Choirce). He describes his childhood in a remote Irish-speaking community in his memoir Light on Distant Hills.
 The first poems that engaged his attention were those of Robert Burns, read to him by his father. His English teacher at the Gairmscoil in Gortahork encouraged the young Ó Searcaigh to write; he is mentioned under the pseudonym 'Mr Lally' (in Light on Distant Hills Part 3, pp 147-164).
 In the early 1970s, he worked as a barman in London. Later he attended the NIHE (National Institute for Higher Education) in Limerick where he did European Studies for two years (1973–75) and followed that with one year at Maynooth University (1977–78) where he did Celtic Studies.
 From 1978 to 1981, he worked in Dublin with RTÉ television presenting Aisling Gheal, an arts and music programme directed by musician Tony MacMahon. From the early 1980s, he has earned his living as a full-time writer and poet.
 In the spring of 1995, he was elected a member of Aosdána.
 His work has been translated into numerous languages – French, German, Italian, Breton, Catalan, Polish, Danish, Serbo-Croat, Romanian, Slovene, Russian, Swedish, Japanese, and Nepali. His poems have been on the Leaving Certificate Irish language curriculum and are also studied at university level.
 Ó Searcaigh began to visit Nepal and sponsor the education and needs of youngsters in Nepal in 1996. The Garda Síochána (Irish police force) started to investigate Ó Searcaigh in 2006, though nothing ever came of this.
 In February 2007, a film documentary (Fairytale of Kathmandu, by Neasa Ní Chianáin) queried the ethics of Ó Searcaigh's sexual relationships with some of the teens he helped, focusing on power imbalance and financial accountability, causing some controversy. In February 2009, Ó Searcaigh was interviewed in English by Dermod Moore on the controversy for Hot Press.
 Ó Searcaigh has donated his archives, an extensive library of books and a valuable art collection to the Irish State.  The Donegal Library Service administers this donation at present. His house in Mín a' Leá at the foot of Mount Errigal is often the venue for literary and musical evenings hosted by the poet himself.
 He edits Irish Pages, a literary journal, along with poet and literary critic Chris Agee.
 "Creativity for me arises out of my deep attachment to this place, out of a reverential affection for its people", he says in his memoir Light on Distant Hills. "My poems are devotional in the sense that they are prayerful celebrations of place, tongue and tradition. My work has become known because of its connectedness with this place. I have become a collector of its oral traditions, an archivist of its memories and its myths, a guardian of its Gaelic. This is, I suppose, a political act, acknowledging the local, recording and registering what is past or passing."
 Colm Tóibín wrote in the Times Literary Supplement: "There is a section of landscape in Donegal in the north of Ireland near Falcarragh, overlooking Tory Island, which has been utterly transformed by the poetry of Cathal Ó Searcaigh."
 Cathal has also collaborated with Altan, Brian Kennedy, Diana Cannon and many other well-known musicians.