Gill, Thomas Patrick (1858–1931), journalist, politician, and secretary of the Department of Agriculture and Technical Instruction, was born 25 October 1858 at Ballygraigue, Nenagh, Co. Tipperary, the first of the four sons of Robert Gill, a civil engineer who was assistant county surveyor, and Mary (née Clampett), daughter of a woollen merchant, James Clampett of Mount Kennett, Limerick. Robert's elder sister, Mary, was mother of John Augustus O'Shea (qv); his elder brother, Patrick (d. 1883?), who emigrated to America, was editor of the Staten Island Leader; his younger brother, Peter (d. 1891), was editor of the Tipperary Advocate and an unsuccessful parliamentary candidate in the county. T. P. Gill attended the Christian Brothers’ School, Nenagh, and St John's College, Kilkenny. He matriculated at TCD (26 January 1876) and studied engineering, but no record of graduation has been found.
While a student he contributed to the Freeman's Journal a series of articles, ‘The famine fever’, which attracted attention in parliament. On 15 October 1881 he started a local, pro-Land-League newspaper, the Tipperary Nationalist (Thurles), which he edited until its demise in 1882. He was associated with William O'Brien (qv) in the editing of the Parnellite weekly, United Ireland. After the suppression of the Land League, he went (June or July 1883) to the USA, where he edited the Catholic World (New York) and contributed to the North American Review. Much later (1898–9) he was editor of the Unionist Daily Express (Dublin) when it was owned by Horace Plunkett (qv). In November 1885, Gill was elected MP for South Louth. The running of the Plan of Campaign, the new agrarian agitation started by O'Brien and John Dillon (qv), was left largely in Gill's hands, but he managed, unlike many others, to avoid arrest, and in the autumn of 1890 he accompanied O'Brien, Dillon and three other home-rule MPs on a fund-raising tour of the USA. After the home-rule party split (6 December) they returned promptly and took part in negotiations, held in France, to restore unity (25 December to 12 February 1891). Gill acted as an unofficial secretary and aide, going to London and on several occasions meeting the Liberal chief whip, John Morley (qv) (12–28 January 1891).
As the split endured, Gill did not stand for parliament again but devoted himself to practical measures for the improvement of the Irish economy. In association with Plunkett (who called him ‘a practical Thomas Davis’) he took part in the organisation of the round-table conference that resulted in the formation of the recess committee of Irish MPs of all parties (1895–6). He served the committee as secretary and by undertaking an investigation of agricultural education and development in various continental countries which came to be the basis of the committee's report. When, largely as a result of the committee's work, the Department of Agriculture and Technical Instruction for Ireland was set up in 1900, Gill was appointed secretary. As such he was the chief framer of its organisation and policy and author of many addresses and papers on agricultural development. His knowledge of Irish rural life and his custom of travelling widely to give public lectures helped the department, though based in Dublin, to keep closely in touch with the country as a whole. Gill was chairman of the departmental committee on Irish forestry (1907–8), a member of the departmental committee on agricultural credit (1913–14), special representative in the USA for negotiations for removal of embargo on importation of Irish potatoes (1913–14) and administrator of food production and distribution schemes set up during the first world war. He represented Ireland at the general assembly of the International Institute of Agriculture in Rome (1905) and at its first post-war session was chairman of its committee on economic and social policy (1920). He was also a commissioner of intermediate education (1909–23) and a senator of the NUI.
After his retirement from the secretaryship of the Department of Agriculture and Technical Instruction (1923), he served as chairman of the Irish Free State central savings committee. A raconteur with (in the words of R. A. Anderson (qv) who knew him well) ‘a queer charm about him’, Gill moved in Dublin literary circles (he is caricatured in George Moore's Hail and farewell! (1911–14)), and in his retirement he made a translation of Louis Paul-Dubois’ Le drame irlandais et l'Irlande nouvelle (1927), published posthumously as The Irish struggle and its results (1934).
T. P. Gill married (1882) Annie Fennell, daughter of John Fennell of Dublin; they had two sons, Donat and Roy, and a daughter Finola. In his last years he lived at Glenageary, Co. Dublin. He died 19 January 1931 in a Dublin hospital. His younger brother, Robert Paul Gill (1863–1928), was a civil engineer employed by Tipperary North Riding County Council and (with his second wife) father of Tomás Mac Giolla (b. 1924), lord mayor of Dublin, who was named after him. T. P. Gill's papers are in the NLI (MSS 13478–13526).