Plutonium is a radioactive chemical element with symbol Pu and atomic number 94.
Plutonium may also refer to:
- a ploutonion (Latin: plutonium), any of several places where the Greco-Roman god Pluto was worshipped, particularly
- Pluto's Gate, the plutonium near the hot springs at Pamukkale in Turkey (ancient Phrygian Hierapolis)
- Plutonium, a genus of centipedes
- Plutonium, a fictional drug depicted in Clark Ashton Smith's "The Plutonium Drug"
- Plutonium Nyborg, a fictional drug in the film Heavy Metal