| Official Name: | Castleleiny |
| Native Name: | Irish: Caisleán Laighnigh |
| Native Name Lang: | ga |
| Settlement Type: | Village |
| Pushpin Map: | Ireland |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location in Ireland |
| Subdivision Type: | Country |
| Subdivision Name: | Ireland |
| Subdivision Type1: | Province |
| Subdivision Name1: | Munster |
| Subdivision Type3: | County |
| Subdivision Name3: | County Tipperary |
| Unit Pref: | Metric |
| Population As Of: | 2006 |
| Population Density Km2: | auto |
| Utc Offset1: | +0 |
| Timezone1 Dst: | IST (WEST) |
| Utc Offset1 Dst: | -1 |
| Coordinates: | 52.786°N -7.7895°W |
| Blank Name: | Irish Grid Reference |
Castleiney, officially Castleleiny and historically "Castlelyny",[1] is a village in County Tipperary, Ireland. It is one half of the Roman Catholic parish of Loughmore-Castleiney.[2] It is in the barony of Eliogarty.
It is approximately 5 km from Templemore and approximately 7 km from Loughmore. The village is sometimes known locally as The Washpen. There is a stone attesting to this fact erected in the village. The village is reached from Templemore by taking the R433 road out of Templemore and turning right onto the R502, crossing the bridge over the Dublin to Cork railway and the first right onto the L3205 local road towards Castleiney village.
Martin Stanislaus Brennan (1845-1927) - American Catholic priest and scientist known for writing books about religion and science Saint Louis, Missouri..