In a different context, one of our community members cautioned against premature connectivitis syndrome (PCS) when connecting up people, and I think the advice to "think INCHWORM (rather than leapfrog)" is equally valuable here, when you are thinking about a place name.
Your question suggests you already know that civil parishes and Catholic parishes in Ireland are two differnt things. But the goal of finding someone's birthplace in Ireland is to identify the townland. IrelandXO's Guide What is a townland? says:
Townlands are the smallest subdivision of a geographical division of
land in Ireland. They are of no small importance to the family
historian because they can provide a traceable address to the present
day, especially for ancestors who lived in rural or less populated
They also say the townland "pre-dates the Norman invasion and is the smallest territorial unit to have survived since medieval times."
Their research guide has research strategies and links to sites that can help you identify the townland from clues like the one you've found in this record. Look for other records in the US to see if you can get more information. Did John Stewart naturalize? Can you find an obituary? Do you have a place of origin in Ireland for other members of his family, his associates, his neighbors?
Search widely and exhaust all known US records before you try to leap across the water to Ireland on the basis of one clue.
Special caution: When correlating information from records, be aware that the place name reported as where someone is "from" can change depending on circumstances.
- People who were born in a very small place may give the name of the nearest larger town when asked "Where are you from?" because the hearer is more likely to know the larger town than the smaller one.
- People whose family moved when your person of interest were very young may be come to known as "from" the second place when it is not their actual birthplace.
It is because of pitfalls like this that makes depending on just one record perilous. When you put the reported birthplaces on a timeline, and better yet, when you can examine the reported birthplaces for an entire group of siblings, migration patterns for the family can be revealed.