Daniel was born in Ardgregane, Monsea, County Tipperary in 1843; the son of David and Anne (née Moloney) Flannery.
He entered Maynooth College in 1862 and was ordained in 1868.
Affectionately known as Father Dan, he served as a Curate in the Parishes of Portroe, Monsea, Kilbarron, Toomevara and Nenagh, where he was instrumental in the conversion of Nenagh Barracks into a Convent and School. He was appointed Parish Priest of Ruan in November 1888, and was later transferred to Silvermines.
The years following the Great Famine were marked by widespread poverty and evictions. He once observed ...
"Truly Madame Tussaud's Chamber of Horrors won't be complete till she has an Irish eviction scene, but no tongue can tell, no brush depict, even partially, all the horrors of an Irish eviction."
He was appointed Vicar General of the Diocese of Killaloe, and Parish Priest of Killaloe in 1905.
Father Dan died on 30th June 1920, and was buried in Killaloe church grounds.
[his portrait is sought]