Thomas Michael Kettle (9 February 1880 – 9 September 1916) was an Irish economist, journalist, barrister, writer, war poet, soldier and Home Rule politician. As a member of the Irish Parliamentary Party, he was Member of Parliament (MP) for East Tyrone from 1906 to 1910 at Westminster. He joined the Irish Volunteers in 1913, then on the outbreak of World War I in 1914 enlisted for service in the British Army, with which he was killed in action on the Western Front in the autumn of 1916. He was a much admired old comrade of James Joyce, who considered him to be his best friend in Ireland, as well as the likes of Francis Sheehy-Skeffington, Oliver St. John Gogarty and Robert Wilson Lynd.

He was one of the leading figures of the generation who at the turn of the twentieth century gave new intellectual life to Irish party politics, and to the constitutional movement towards All-Ireland Home Rule. A gifted speaker with an incisive mind and devastating wit, his death was regarded as a great loss to Ireland's political and intellectual life.

As G. K. Chesterton surmised, "Thomas Michael Kettle was perhaps the greatest example of that greatness of spirit which was so ill rewarded on both sides of the channel [...] He was a wit, a scholar, an orator, a man ambitious in all the arts of peace; and he fell fighting the barbarians because he was too good a European to use the barbarians against England, as England a hundred years before has used the barbarians against Ireland".

Thomas Kettle was born in Malahide or Artane, Dublin, the seventh of twelve children of Andrew J. Kettle (1833–1916), a leading Irish nationalist politician, progressive farmer, agrarian agitator and founding member of the Irish Land League, and his wife, Margaret (née McCourt). One of his brothers was the industrial pioneer, Laurence Kettle.

Andrew Kettle influenced his son considerably through his political activities, having been involved from an early age in the constitutional movement to achieve Home Rule. Andrew joined Michael Davitt in the foundation of the Irish Land League and was one of the signatories of the "No Rent Manifesto". He had adhered to Charles Stewart Parnell in the 1890 crisis, and stood for election as a nationalist candidate on several occasions.

Thomas was raised in comfortable rural surroundings. Like his brothers he was educated at the Christian Brothers' O'Connell School at Richmond Street, Dublin, where he excelled. In 1894 he went to study with the Jesuits at Clongowes Wood College in County Kildare, known as a wit and a good debater. He enjoyed athletics, cricket and cycling and attained honours in English and French when leaving.

Entering University College Dublin in 1897, he was regarded as a charismatic student. Surrounded by ambitious and politically minded young men he quickly established himself as a leading student politician and a brilliant scholar. He was elected to the prestigious position of auditor of the Literary and Historical Society, 1898–1899. His friends and contemporaries at UCD included Hugh Kennedy, Francis Sheehy-Skeffington, Oliver St. John Gogarty and James Joyce.

Tom Kettle distributed pro-Boer leaflets during the early months of the South African Second Boer War, and protested against the Irish Literary Theatre production of Yeats' The Countess Cathleen in 1899 over its irreligious story of an unlikely kind-hearted aristocrat who sells her soul to save her tenants. Due to illness he interrupted his studies in 1900, his health always being fragile. He went abroad to renew his spirits by travelling on the continent, improving his German and French. Returning to Dublin he renewed his studies, and in 1902 took a BA in mental and moral science. ^{[citation needed]}