Answer:
To a certain extent but its arguable and most would agree they didn't. The Irish employed the Brehon laws for much of its history before invasions, which as far as I know didn't have slavery, but there was a monacrhy of sorts so presumably there was a form of serfdom that could be considered slavery but essentially Ireland was a nation of warring tribes each claiming to be rightful ruler of the land. Vikings and Normans invaded Ireland and they did utilize slavery and participated in the slave trade between Europe and Britain. The Irish fought against these invaders but as of course is they way of things there was some inevitable interbreeding so it comes down to what you define as Irish.
Later still, Ireland came under the control of the British Empire so the Irish themselves became slaves.
So essentially: No