Lynn (Irish: Lainn) is a civil parish in County Westmeath, Ireland. It is located about 4.31 kilometres (3 mi) south–south–east of Mullingar.
Lynn is one of 10 civil parishes in the barony of Fartullagh in the Province of Leinster. The civil parish covers 4,905.3 acres (19.851 km2).
Lynn civil parish comprises 12 townlands: Ardillon, Burnellstown, Catherinestown, Clonmoyle, Lynn, Gainestown, Glendevine, Gorteen, Lynn, Tornanstown. Tullanisky and Vilanstown.
The neighbouring civil parishes are: Mullingar to the north, Killucan (barony of Farbill), to the east and Enniscoffey and Moylisker to the south.