The IRFU Interprovincial Championship was a rugby union competition between the four provinces of Ireland – Ulster, Leinster, Munster and Connacht – run by the Irish Rugby Football Union. It was run as a distinct competition from 1946–47 to 2000–01,[1] with the 2001–02 fixtures being fulfilled by the match-ups in the newly formed Celtic League.[2] For a time in the 1980s, the IRFU ruled that Irish diaspora players should play for Connacht, in an attempt to strengthen the weakest of the four provinces.[3] The Irish Exiles took part for four years (1992–93 – 1995–96).[1]
In 2021, the United Rugby Championship introduced regional shields with the Irish provinces competing for the Irish Shield. Initially the pool included results against other non-Irish sides but from 2023 onwards, the URC announced that the regional pool shields of the competition would be decided only by results between the teams within each pool. With this change, the URC effectively reintroduced the Interprovincial Championship in its original format for the first time since 2002.