Thomas O Brien

[ballydw]

Death of Angela O’Brien - informant James, Ballymuddy.
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1875/020611/7231879.pdf

Marriage Thomas Brien and Angela Devine
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1874/11232/8118118.pdf

I was hoping that a witness might be a sibling to Thomas so you could find baptism records.

Angela O Brien (Devine) died 21st July 1875. Thomas O Brien remarried 8th July 1876 to Ellen Russell

[heywood]

Death of Betty Brien of Fountain
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1888/06174/4764895.pdf

[ballydw]

Death of Betty Brien of Fountain
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1888/06174/4764895.pdf

Great find Heywood Betty wife of James presume her name would be Elizabeth. I am trying to connect these O Briens with a Ellen Brien born June 1817 same area of James O Brien. Ellens parents were John O Brien Mary Dunne. James going by his death record was born c 1806. Its a mammoth task especially with the Surname. Ellen ended up in USA and to make matters more confusing she married here to a William O Brien - some of their children being born in Ireland. I believe they immigrated to USA circa 1853

[Wexflyer]

I am a little perplexed.
What would be the benefit of finding the baptism/parents of this Thomas, as OP is not descended from him, and in fact knows his ancestry further back already?

Apart from that, is it certain that Fountain and Ballymuddy are in the parish of Lismore?
Looking at a map, seems to me that Tallow must be a possibility.