Pre-history
Ogham alphabet
14th century
Whiskey
17th century
1661: Modern Chemistry founded by Robert Boyle with the publication of The Sceptical Chymist
1662: Boyle's law discovered by Robert Boyle
18th century
1730: The concept of an entrepreneur - Richard Cantillon
1752: National Hunt racing
19th century
1805: Beaufort scale created by Francis Beaufort
1813: Clanny safety lamp created by William Reid Clanny
1820: 30 January, Edward Bransfield discovered the Antarctic Continent (mainland, islands were discovered earlier)
1820-25: The development of "Extra Stout" beer by The Second Arthur Guinness and others.
1831: Column still design enhanced and patented by Aeneas Coffey
1832: The Kyanizing process for preserving wood, created by John Howard Kyan
1834-35: The game of Croquet
1836: Induction coil created by Nicholas Callan
1843: Quaternion (a mathematical entity) first described by Sir William Rowan Hamilton
1844: Hollow needle in syringe created by Francis Rynd
1848: Kelvin scale created by William Thomson
1851: Seismology founded by Robert Mallet, who used dynamite explosions to measure the speed of elastic waves in surface rocks - pioneering and coining the word 'seismology'.
1851: Binaural stethoscope created by Arthur Leared
1866: The Standard drop method of hanging developed by Dr Samuel Haughton
1874: Electron introduced as a concept by George Johnstone Stoney
1874: Brennan torpedo created by Louis Brennan
1879: The rules of Hurling first standardized with the foundation of the Irish Hurling Union
1880: Boycott triggered by Charles Boycott over a dispute with the Irish Land League
1884: Steam Turbine: Compound Steam Turbine developed by Anglo-Irish engineer Charles Algernon Parsons. The Parsons family were resident in Birr, Co. Offaly.
1888: Gregg Shorthand created by John Robert Gregg
1894: Joly colour screen created by John Joly
1891: Tattoo machine created by Samuel O'Reilly
1897: Modern submarine design created by John Philip Holland.
Saccharimeter created by Rev John Jellet from Cashel, County Tipperary (1817–1888)
20th century
1900: Reflector sight created by Howard Grubb.
1910s: Radiotherapy developed by John Joly.
1926: Three point linkage, patented by Harry Ferguson.
1930: Nickel-zinc battery created by Dr. James Drumm.
1930s: The first disintegration of an atomic nucleus by artificially accelerated protons (splitting the atom) discovered by Ernest Walton et al
1946: Ejection seat - first live test of a reliable, successful modern ejection seat developed by James Martin
1954: Clofazimine first synthesized by a medical research team led by Cork man Vincent Barry at Trinity College, Dublin.
1965: Portable defibrillator created by Frank Pantridge.
1967: Pulsar co-discovered by Jocelyn Bell Burnell.
1970s: Positive end-expiratory pressure technique for treatment of pulmonary contusion - developed by staff at the Royal Victoria Hospital, Belfast.
And, while we're at it, Guerrilla Warfare.