Russagh () is a civil parish in County Westmeath, Ireland. It is located about north–west of Mullingar.
Russagh is one of 6 civil parishes in the barony of Moygoish in the Province of Leinster. The civil parish covers .
Russagh civil parish comprises 9 townlands: Barratogher, Cappagh, Corrydonellan, Loughanstown, Loughanstown Lower aka Slievelahan, Rathowen, Russagh, Slievelahan aka Loughanstown Lower, Windtown North and Windtown South.
The neighbouring civil parishes are: Street to the north, Lackan (barony of Corkaree) to the east, Kilbixy to the south and Mostrim (barony of Ardagh, County Longford and Rathaspick to the west.