Arnionys is a village in Molėtai District Municipality, in Utena County, Lithuania. It has 147 inhabitants (2021). The nearest city is Vilnius, 50 km to the southwest. Near the border: Belarus, 17 km. Among the landmarks around are Dubingiai Castle (17.4 km), Church of St. James the Apostle, Joniškis (3.9 km) and Church of St. Casimir, Pavoverė (11.9 km).

Also written Arnionys I.