is st patricks day a catholic or an irish holiday?

It is a day for both but is especially big in Ireland.

It follows both

im pretty sure its a world wide practice, however its mostly celebrated as an Irish holiday.  St Patrick was (confirmed) by the current pope as one documentary on youtube says. another documentary i views said that he was only a very recent relative to one of the disciples.

Both. Saint Patrick's Day became a holy day of obligation for Roman Catholics in Ireland. It is also a feast day in the Church of Ireland, which is part of the worldwide Anglican Communion.

It's a green beer holiday.

Irish..........................