| Official Name: | Vailainiai |
| Settlement Type: | Village |
| Pushpin Map: | Kėdainiai District Municipality#Lithuania |
| Pushpin Map Caption: | Location in Lithuania |
| Subdivision Name: |  Lithuania |
| Subdivision Type1: | County |
| Subdivision Name1: | Kaunas County |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Kėdainiai district municipality |
| Subdivision Type3: | Eldership |
| Subdivision Name3: | Krakės Eldership |
| Population As Of: | 2011 |
| Population Total: | 23 |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
| Coordinates: | 55.4781°N 23.6669°W |
Vailainiai (formerly ru|Валайне, pl|Wajłajnie) is a village in Kėdainiai district municipality, in Kaunas County, in central Lithuania. According to the 2011 census, the village had a population of 23 people. It is located from Barkūniškis, by the Šušvė river (and its tributaries the Krimslė and the Vinkšnupis), alongside the Grinkiškis-Krakės road. There is a cemetery.