Glassan (Irish: Glasán, meaning "small stream") is a small village of 216 inhabitants (2002 census) in rural County Westmeath, Ireland. It is 10 km (6.2 mi) north of Athlone, on the N55 national secondary road, not far from the shores of Lough Ree. A small river known as the River Tullaghan flows through the northern end of the village and then flows south to Killinure Lough, a part of Lough Ree.