Vilainiai (formerly Russian: Вилайни, Polish: Wiłajnie) is a village in Kėdainiai district municipality, in Kaunas County, in central Lithuania. According to the 2021 census, the village had a population of 1157 people. It is located next to the north eastern edge of Kėdainiai, on the left bank of the Nevėžis river. There is a kindergarten, a library, a sports school, a culture house, Water Management Institute of Vytautas Magnus University Agriculture Academy.