Ó Súilleabháin, Tomás Ruadh (1785–1848), schoolmaster and poet in Irish, was born in Bán Ard, Derrynane, Co. Kerry. His father, a relation of Eoghan Rua Ó Súilleabháin (qv), may have been called Tadhg and his mother's maiden name was Sugrue. The little that is known of his life has been gleaned from his songs, which indicate that he travelled throughout Munster and spent time in Killarney, Cork, Limerick, Kilkenny, north Kerry, Dingle, and Dublin. Tomás received his earliest education in a school in Gort na Cille. He appears to have received patronage from the O'Connell family; according to Séamas Ó Fiannachta, sometime after 1818 he was sent by Daniel O'Connell (qv) to a teacher training college in Dublin, possibly that of the Kildare Place Society. O'Connell was a member of the Society's board until 1820. During Tomás's third year in college he contracted tuberculosis and was sent to the sanatorium on Cork St. by Seán Ó Riordáin, MD, a relation of O'Connell. While there he composed his best-known hymn, ‘A Rí an Domhnaigh’, in which he called on God and the Blessed Virgin to come to his assistance. After leaving Dublin he taught in various Co. Kerry schools including Caherdaniel, Portmagee, Aghatubrid, Ballinskelligs, Waterville, Cill Péacáin, Poll na nGeatairí, Drom Caor, Glenbeigh, and Séipéal an Chomhaid.
His poems provide an interesting insight not only into his own life but into contemporary life in the Iveragh area. The themes are taken from occurrences that happened either to him or to those around him. He regularly attended social gatherings, accompanying his songs with a tune on the fiddle. An enthusiastic supporter of Daniel O'Connell, Tomás Ruadh wrote a number of songs in his honour, including two on the occasion of O'Connell's election as an MP for Co. Clare in 1828: ‘Guím slán go hUíbh Ráthach’ and ‘Is é Donall binn Ó Conaill caoin’. Another poem, ‘An Gheadach á crú sa Ghleann’, voiced the hope that an end would soon come to the payment of tithes, and is said to have been composed after the confiscation of a widow's only cow in lieu of payment. The song ‘A Bhrasby, Taoi ar Buile’ called on the catholic priest Fr Denis Leyne Brasbie, who had converted to protestantism in Dingle in 1844, to return to the catholic church.
His ‘Amhrán na leabhar’, which was later adapted by Austin Clarke (qv) in Flight to Africa (1963), is a lament for a valuable collection of books and manuscripts he lost when the boat in which they were being transported capsized during a crossing from Doire Fhionáin to Portmagee. Ó Súilleabháin's list of the books lost included the History of Ireland (1778) by Sylvester O'Halloran (qv), Parrthas an Anma (1645) by Antoin Gearnon (qv), Eochair-Sciath an Aifrinn (1610–13) by Geoffrey Keating (qv), and books by Thaddeus Connellan (qv), among others. The song ‘Síghle Ní Ghadhra’ provided an account of Irish history as told in Keating's Foras Feasa ar Éirinn (1634). Ó Beoláin suggests that it may have been composed for the purpose of teaching his pupils history, and argues that although it is worthless as a piece of poetry, the versification is clever.
Ó Súilleabháin never married and died in 1848. He was buried in Achadh Mhór near Doire Fhionáin. A memorial plaque was erected on his grave in 1928.