The Irish National Cycling Championships are annual cycling races to decide the Irish cycling champion for several disciplines, across several categories of rider.

The men's road championship is usually held on a Sunday at the end of June; the women's race is held the previous day. The winning élite rider wears the national champion's jersey for all road races in the following 12 months. Unlike most countries, the jersey does not contain the national flag or stripes from the flag's colours; instead, the jersey has a wide green band superimposed with a shamrock, the national flower of Ireland. The men's under-23 champion is awarded to the first under-23 in the élite race. The junior road races are held on the same day as the élite and the time-trial championship is held earlier in the week. The national criteriums are held later in the summer.

Courtesy Quay Cycles, Drogheda

1875–1905: Richard J. Mecredy, Arthur du Cros, Charlie Pease, Bob Reynolds 9 Championships each, Harry Reynolds 5 Championships, R. Hassard 6 Championships

25ml track: 1889: Arthur du Cros; 1890 & 1891 R.J. Mecredy; 1895: Harry Large; 1896: Harry Reynolds; 1909 Sam Cochrane; 1924 Culvenor Gibson.

50ml track: 1876: H. H. Law; 1896: M. S. Walsh;

1890s R. J. Mecredy won the 2nd 100ml championship

Inter Club Team Championship: 1886, 1887: Leinster C.C.