Ireland is still pretty free and easy and wild camping is acceptable. Overnight camping is not permitted at most popular tourist attractions but if you move a few miles down the road you will surely find a beautiful location to stop and camp.
There are a couple of good wild-camping resources you can refer to online:
> Camper Contact – a general listing for camper spots… some of them free.
> park4night – a listing of places you can pull up & park for the night.
> Total CampingIreland – Legal Stopovers – Lists all of the designated overnight spots, also know as Aires De Service for campervans and motorhomes. Some are purpose-built and run by the local authorities.