Thomas Derrig (Irish: Tomás Ó Deirg; 26 November 1897 – 19 November 1956) was an Irish Fianna Fáil politician who served as Minister for Lands from 1939 to 1943 and 1951 to 1954, Minister for Education from 1932 to 1939 and 1940 to 1948 and Minister for Posts and Telegraphs in September 1939. He served as a Teachta Dála (TD) from 1921 to 1923 and 1927 to 1957.^[1]

Derrig was born on 26 November 1897, in Westport, County Mayo, the son of Patrick Derrig and Winifred Derrig (née Sammon).^[2] He was educated locally and later at University College Galway.

During his time in college he organised a corps of the Irish Volunteers. Derrig did not take part in the 1916 Easter Rising but was arrested in the aftermath. He was imprisoned in Woking, Wormwood Scrubs and Frongoch internment camp. He was arrested in July 1918, and was accused of attempting to disarm a soldier. He was sentenced to five months imprisonment by a court in Belfast. When he was released in November 1918, he supported Joseph MacBride at the 1918 Irish general election. After his release, he graduated from college and became headmaster in a technical college in Mayo.^[3]

During the Irish War of Independence he was the Brigade Commandant of the West Mayo Brigade of the Irish Republican Army, before being captured in January 1921 and interned at the Curragh Camp.^[4] While there he was elected a Sinn Féin TD for Mayo North and West.^[5] During the Truce period, he was appointed Divisional Director of Organisation of 4 Western Division IRA.

Taking the anti-Treaty side in the Irish Civil War, Derrig took part in fighting against National forces in Dublin. He escaped from Dublin on 30 June 1922 and served as Adjutant to Ernest O'Malley during fighting in counties Wicklow and Wexford in July and August. Derrig was appointed IRA Adjutant General by Liam Lynch in November 1922 and was serving in that position when arrested by National Forces on 6 April 1923. On that same date, while in custody of the Criminal Investigation Department in Oriel House, Derrig was shot in the face by a CID detective and lost his left eye. Derrig was interned at Kilmainham Gaol and was a leader there during the 1923 Irish hunger strikes^[6] Derrig was later awarded a wound pension under the Army Pensions Act, 1932 for the gunshot wound he received while in custody. Derrig also applied to the Irish government for a service pension under the Military Service Pensions Act, 1934 and was awarded 7 and 3/8 years service in 1942 at Grade A for his service with the Irish Volunteers and the IRA between 1 April 1917 and 30 September 1923. ^[7]

In 1928, he married Sinéad Mason of Ards, County Down; they had two daughters.^[2]

At the June 1927 general election he was elected to Dáil Éireann as a Fianna Fáil TD for Carlow–Kilkenny. In Éamon de Valera's first government in 1932 Derrig was appointed Minister for Education. Derrig initiated a review of industrial and reformatory schools and the rules under the Children Act 1908, resulting in the critical 1936 Cussen Report that followed which he shelved, and a report in 1946–1948 by the Irish-American priest Father Edward Flanagan, which was also shelved. His lack of action was noted in 2009 when the Ryan Report examined the subsequent management of these "residential institutions"; Derrig was the first Minister to seek a report that could have resulted in much-needed reforms. It has been suggested that he did not want to follow British law reforms in the 1920s and 1930s, because of his strong anti-British views, and that Irish children had suffered needlessly as a result.^[8]

From 1939 to 1943, he served as Minister for Lands. He was re-appointed to Education in 1943 until 1948. During this period a bitter teachers' strike, involving the Irish National Teachers' Organisation (INTO), took place, lasting from 20 March to 30 October. Between 1951 and 1954, he became Minister for Lands again.

Thomas Derrig died in Dublin on 19 November 1956, seven days before his 59th birthday.^[9] No by-election was held for his seat.