| Official Name: | Kalna |
| Pushpin Map: | Serbia |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: |  Serbia |
| Subdivision Type1: | District |
| Subdivision Type2: | Municipality |
| Unit Pref: | Imperial |
| Population As Of: | 2002 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 43.4089°N 22.4264°W |
Kalna (Serbian: Кална) is a small village in the Knjaževac municipality of the Zaječar District of Serbia.
Kalna is known for the only finding of uranium in Serbia. Preparations were made for the extraction of ore and the opening of a mine, but the project failed. Later, the village was subject of some controversy after allegations were made in the press in the early 1990s that the empty facilities of the doomed mine were used as a dumping place for radioactive waste from Western Europe. Despite months of high publicity in the press, these allegations were never proved to be true.