Protium may refer to:
- In physics and chemistry, protium refers to hydrogen-1, the most common isotope of the element hydrogen, with one proton and no neutrons
- Protium (plant) refers to a genus of chiefly tropical American trees in the family Burseraceae, having fragrant wood
- Protium (computer language) is a universal, symbolic programming language system
- In medicine, Protium is a commercial name for pantoprazole, a so-called "proton inhibitor" drug