| Official Name: | Vajska |
| Settlement Type: | Village (Selo) |
| Pushpin Map: | Serbia Vojvodina#Serbia#Europe |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: |  Serbia |
| Subdivision Type1: | Province |
| Subdivision Type2: | Region |
| Subdivision Name2: | Bačka (Podunavlje) |
| Subdivision Type3: | District |
| Subdivision Name3: | South Bačka |
| Subdivision Type4: | Municipality |
| Subdivision Name4: | Bač |
| Unit Pref: | Imperial |
| Population As Of: | 2011 |
| Population Total: | 2,834 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 45.4167°N 26°W |
Vajska (Serbian Cyrillic: Вајска ; Romanian; Moldavian; Moldovan: Vaisca) is a village in Serbia. It is situated in the Bač municipality, in the South Bačka District, Vojvodina province. Two neighbouring settlements, Labudnjača (Serbian: Лабудњача; 45.45°N 21°W) and Živa, are also officially regarded as parts of Vajska although they are physically separated from it. The name Labudnjača is derived .
In Serbian the village is known as Vajska (Вајска), in Croatian as Vajska, in Hungarian as Vajszka or Józsefháza, in German as Wajska and in Romanian as Vaisca.
During the early stage of the Yugoslav Wars and following the Battle of Borovo Selo in neighbouring Croatia, Danube river link was established between Vajska and Borovo 4 of May 1991 which during its operation reportedly served between 10-30,000 passengers including Croat refugees leaving the village of Borovo.[1]
The population of the village numbered 2,834 people as of the 2011 census.[2] In 2002, the population included 1,319 Serbs, 569 Romanians, 353 Croats, 341 Hungarians, 207 Yugoslavs, and others.