Ó Donnchadha an Ghleanna, Séafraidh (O'Donoghue of the Glen(s), Geoffrey) (c.1620–1678), poet and chief of the O'Donoghues of Glenflesk, Co. Kerry, was one of three sons of Tadhg Ó Donnchadha an Ghleanna, and Eibhlín, daughter of Tadhg Óg Ó Cruadhlaoich. He acceded to the chieftaincy around 1643 following his father's death. Despite having taken part with his father and two brothers in the siege of Tralee (1641) he managed, in contrast with many of his peers, to retain his estate in Glenflesk throughout the Cromwellian period.
His generosity and love of learning were renowned among poets, and the ancestral home of the O'Donoghues of the Glen, Killaha Castle (a tower house probably built at the end of the sixteenth century and still standing in a ruined state four centuries later), served as a focal point for men of learning during his reign. One of a number of poems which celebrate his hospitality and patronage was composed on a visit during 1642–3 by the Outer Hebrides poet Maoldomhnaigh Ó Muirgheasáin, who was one of the last bearers of a tradition whereby Gaelic-speaking poets from Scotland toured Ireland.
Ó Donnchadha composed in both syllabic and accentual metres and a number of his poems are to be found in Dánta Shéafraidh Uí Dhonnchadha an Ghleanna (1902), ed. Pádraig Ó Duinnín (qv). This volume contains a mix of elegies, political poems, and other compositions. One of his most popular poems, ‘Is brónach mo thocht’, is unusual in both its subject matter and metre: composed to the tune of an older piece of music, it is a lament to his beloved spaniel which had met its demise by choking on a mouse. Also noteworthy are ‘Is barra ar an gcleas an reacht do théacht tar tuinn’, which powerfully criticises Charles II's confirmation of the division of land made under Cromwell (qv), and ‘Ní fhulaingid Goill dúinn síothughadh i nÉirinn seal’, which angrily addresses the changes brought about by the Cromwellian plantations. Although he is not regarded as one of the great poets of the period, his work has been admired for its fluency and dexterity of language. The much praised poem ‘Do chuala scéal do chéas gach ló mé’, usually ascribed to Piaras Feiritéir (qv), is attributed to Ó Donnchadha in some manuscripts. Several of his compositions remain unedited.
He married first (a.1643) Siobhán, second daughter of Domhnall Mac Fínghin and Elizabeth Stephenson, and later Alice, eldest daughter of Dominick Coppinger of Cork and Mary Coppinger (née Comine). He died in 1678 and was survived by Alice and three children, one of whom, Domhnall, was his heir. He is believed to be buried in the O'Donoghue tomb in the chancel of Muckross friary near Killarney and is commemorated, along with other famous Kerry poets Piaras Feiritéar, Aogán Ó Rathaille (qv), and Eoghan Rua Ó Súilleabháin (qv), on a monument erected through the efforts of Pádraig Ó Duinnín in 1940 outside the Franciscan friary in Killarney.