| Ballinlassy | |
| Native Name: | Irish: Baile an Leasa |
| Native Name Lang: | ga |
| Settlement Type: | Townland |
| Subdivision Type: | Country |
| Subdivision Name: | Ireland |
| Subdivision Type1: | Province |
| Subdivision Name1: | Leinster |
| Subdivision Type3: | County |
| Subdivision Name3: | County Westmeath |
| Unit Pref: | Metric |
| Coordinates: | 53.3681°N -7.8353°W |
Ballinlassy is a small townland in the civil parish of Kilcleagh and the historical barony of Clonlonan in County Westmeath, Ireland.[1] Located near the village of Ballynahown, Ballinlassy borders the townlands of Cartrons, Killomenaghan & Farranmanny South to the north, Curraghbeg & Kilbillaghan to the west and Castletown to the east.[2] The River Boor flows through the townland.[3] Ballinlassy, which has an area of approximately 0.7km2,[2] had a population of 27 as of the 2011 census.[4]