Ismonys is a village in Trakai District Municipality, in Vilnius County, Lithuania. Ismonys lies at 167 m above sea level. It has 103 inhabitants (2021). The nearest city is Vilnius, 38 km to the east. Among the landmarks around are Trakai Island Castle (15.7 km), Basilica of the Visitation of the Blessed Virgin Mary (15.2 km) and Trakai Kenesa (15.4 km).