O'Shea, Thomas (1813–87), catholic priest and agrarian agitator, was born 16 April 1813 at Cappahayden, Kilmanagh, Co. Kilkenny, a son of Thomas Shea or O'Shea, a native of Little River, Callan, and presumably a farmer, who had moved to Cappahayden in 1790. With his wife (née Townsend) Thomas the elder had thirteen other children, one of them, Robert O'Shea (d. 1883), parish priest of Ballyhale. Thomas the younger studied classics at Burrell's Hall, Kilkenny, and logic at Birch-field before entering Maynooth (27 August 1834), where he studied physics and was made a Dunboyne scholar. He was ordained priest for the diocese of Ossory (1840) and, before obtaining charge of a parish, served as curate in St John's, Kilkenny (1840–43), Tullaroan (1843–4), Slieverue (1844–8), Callan (1848–55) and Cullahill (1855–63).
At Callan he collaborated with another priest, Matthew Keeffe (qv), who though a curate was effectively the administrator of the parish, to call a meeting at the town hall and form the Callan Tenant Protection Society (29 October 1849), to give voice to the tenant-farmers of the locality seeking a reduction in their rents in particular from one local landlord, the earl of Desart, the bête noire of the district. It was joined not only by farmers but by merchants and professional men; it proved a model for thirty or so tenants’ associations elsewhere and gave rise to the Tenant Right League, formed at a meeting in Dublin sponsored by Charles Gavan Duffy (qv), John Gray (qv), and Frederick Lucas (qv) (August 1850). Widely regarded as a pioneer of tenant-right agitation, O'Shea was in demand as a public speaker beginning with a by-election in Co. Limerick (December 1850). With the support, or at least the approval, of the league three candidates were returned to parliament for Kilkenny city and county at the ensuing general election and as many as 40 elsewhere (July 1852).
O'Shea ventured north (February 1854) to support an independent candidate, John MacNamara Cantwell, at a by-election in Co. Louth in opposition to the liberal candidate, Chichester Fortescue, seeking re-election upon ministerial appointment and the preferred candidate of the local bishop, Joseph Dixon (qv), and of the papal legate, Paul Cullen (qv). It appears that during the campaign both Dixon and Cullen may have asked O'Shea's bishop, Edward Walsh (1791–1872), to recall him and to restrict him to Ossory. A few months later Keeffe wrote a reproachful letter to one of the Kilkenny MPs, William Shee (1804–68), who published it thereby drawing it to the attention of Walsh, a friend of Shee (23 October). Keeffe was immediately silenced by Walsh. Coincidentally, a public meeting in support of tenant-right had been arranged for Callan on 29 October 1854; some ten thousand attended including (as representatives of the Tenant League) Duffy and Lucas. O'Shea spoke up against Shee and for Keeffe, for which he too was suspended shortly afterwards; Lucas, self-opinionated and stubborn, shared the indignation of the crowd that O'Shea and Keeffe had been unfairly treated and, believing that Walsh's action had been at the behest of Cullen, took it upon himself to go to Rome to seek remedies for this and other grievances. It was a futile gesture. Both O'Shea and Keeffe were soon moved by Walsh to other parishes. After 1852 the Callan Tenant Protection Society ceased to function.
O'Shea was eventually appointed parish priest of Comers (Camross), near Mountrath, Queen's Co. (January 1863). This gave him more independence, but he behaved improperly as an Ossory priest in campaigning in the Waterford diocese at the general election held in November 1868. O'Shea supported Henry Matthews who was standing at Dungarvan against a Liberal, Charles Barry (1824–97), the candidate of the local bishop. During the 1870s, which saw the rise of the home-rule movement of Isaac Butt (qv), O'Shea was a prominent member of Queen's County Independent Club, one of the first such clubs to declare for Butt (January 1871), and was active in home-rule politics at a national level. At the Home Rule League conference in Dublin on 11 October 1877 he sided with Butt in the challenge to his leadership presented by Charles Stewart Parnell (qv). The Land League, which Parnell led, received only qualified support from O'Shea, as he made clear at a meeting to form a Mountrath branch (14 November 1880): ‘I am not here to speak against landlords as a whole . . . [or] against just and fair rents’. Father Tom O'Shea (as he was affectionately called) died 30 March 1887 at Crannagh Cottage; Keeffe, by then parish priest of Aghaboe, near Ballacolla, died some nine months later (28 November 1887). A photograph of O'Shea in old age is printed by Carter. He was remembered by Duffy as ‘genial and cordial in expression, of dauntless intrepidity and moved by a sympathy and sincerity which were mesmeric’ (League of north & south, 21).