Kalna 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.
Kalna may mean
- Kalna, India, a city in India
- Kalna, Poland, a village in Poland
- Kalna (Crna Trava), a village in Serbia in the Crna Trava municipality
- Kalna (Knjaževac), a village in Serbia in the Knjaževac municipality
- Kálna, the Hungarian name for Calna village, Vad Commune, Cluj County, Romania
Kalna (Vidhan Sabha constituency) is an assembly constituency in Bardhaman district in the Indian state of West Bengal. The seat is reserved for scheduled castes.