Coyne, Thomas Joseph (‘Tommy’) (1901–61), civil servant, was born 22 February 1901 in Dublin, youngest among five children of William P. Coyne (qv), barrister, later head of the statistical section of the Department of Agriculture (and sometime professor of political economy and jurisprudence at UCD), of 122a St Stephen's Green, and Agnes Mary Coyne (née Martin). An outstanding student, he was educated at Clongowes Wood College (1912–17), UCD (MA), and the King's Inns, though before completing his studies he joined the Royal Flying Corps in 1918. Graduating in legal and political science in 1920, he was too young to be called to the bar. The recipient of the Horace Plunkett Foundation Scholarship (1922), he prepared a monograph on the supply and distribution of milk for the commission of inquiry into the resources and industries of Ireland, as well as a special study of co-operative credit.
Eventually called to the bar in 1922, he joined the staff of the judge advocate general of the national army, with the rank of lieutenant-commandant. In January 1923 he entered the civil service as one of the first three junior administrative officers appointed, and succeeded Thomas Finlay (1893–1932) as private secretary to Kevin O'Higgins (qv), then minister for home affairs. Seconded to the Department of External Affairs in 1929, he served first in Rome under Charles Bewley (qv) as secretary to the legation to the Holy See, and later in Geneva as assistant to the permanent delegate to the League of Nations. Recalled to the Department of Justice in 1934 as principal officer, he served (1935–8) on the interdepartmental committee on censorship.
When the committee produced its final report at the end of 1938, Coyne was seconded to the Department of Defence under Frank Aiken (qv) and given responsibility for planning the foundation and development of censorship structures. These were seen as vitally important in view of the perceived threat to Irish security that had arisen with the ever-increasing possibility of war in Europe. In 1938, with P. P. O'Donoghue (qv) of the office of the attorney general, he co-drafted the bill that eventually became the Emergency Powers Act, 1939.
On the outbreak of the second world war Coyne was made deputy controller of censorship, and after the fall of France during the summer of 1940 he became convinced that Ireland faced a very real threat of invasion. He believed the freedom of the press had to give way to the government line in matters of national security until the threat had passed, and this led him to impose a rigid censorship on any discussion of hostilities in Europe. However, when the threat did pass, Coyne favoured allowing the press to discuss foreign affairs, provided that this did not interfere with the policy of neutrality. His view did not find favour with the controller, Joseph Connolly (qv), who was more sceptical of the ability of the press to discuss matters without drawing the attention of those countries involved in the hostilities.
Coyne himself had a low opinion of newspapermen, whose professional interests, he felt, were all too frequently at variance with the interests of the public. He did, however, curb much of the use of the blue pencil by Frank Aiken; and R. M. Smyllie (qv) attributed to him ‘one of the shrewdest and subtlest brains’ in the country. In 1946 he was appointed assistant secretary of the Department of Justice; and in September 1949, on the death of John E. Duff, he was appointed secretary. Throughout his career his disarming and diplomatic nature often assisted in bringing calm to the often strained working environments of many government departments. He retired in February 1961.
Married, he lived at 1 Arranmore Road, Ballsbridge. He and his wife Norah had a daughter who died young after a long illness. His wife, whom he had known since his school days, died in September 1960. Suffering with ill health throughout his life, he entered a Dublin nursing home the day after his wife's funeral and died there 18 May 1961. His brothers were the Rev. Edward J. Coyne (qv), SJ, and P. Coyne, manager of the Hibernian Bank, College Green, Dublin.