thumb|right|County Westmeaths placering
County Westmeath () er et county i Republikken Irland, hvor det ligger i provinsen Leinster.
County Westmeath omfatter et areal på 1.764 km² med en samlet befolkning på 79.403 (2006).
Det administrative county-center ligger i byen Mullingar.
Byer og landsbyer
Athlone Ballinahown Ballinalack Ballykeeran Ballymore Ballynacargy Castledaly Castlepollard Castletown-Geoghegan Clonmellon Collinstown Coole Crookedwood Delvin Drumcree Drumraney Finnea Fore Glassan Horseleap Kilbeggan Killucan and Rathwire Kinnegad Milltownpass Moate Mount Temple Moyvoughly Mullingar, the county town Multyfarnham Raharney Rathconrath Rathowen Rochfortbridge Rosemount Streamstown Streete Tang Tubberclare Tyrrellspass
Seværdigheder Athlone Castle Belvedere House and Gardens Castlelost Castle Clonyn Castle Kilbeggan Distillery Portlick Castle Rattin Castle Tullynally Castle