Furball
Evil Scotsman
Most sports pre-partition were run from Dublin, and the status quo has remained post partition.Only in rugby union and cricket am I aware of any team perporting to represent the in-reality-non-existent "country" that is Ireland.
Football is the most notable exception, as the Irish Football Association, which ran the game in Ireland pre-partition, was based in Belfast. Post-partition, the FAI was formed in Dublin, and those teams who played south of the border resigned from the IFA and re-aligned themselves with the FAI.
I'm fairly certain most sports in Ireland are run on a national level as an "all-Ireland" entity.