Hydrogen is the chemical element with symbol H and atomic number 1.
Hydrogen may also refer to:
- Dihydrogen, an allotrope of hydrogen
- Hydrogen atom, about the physics of atomic hydrogen
- Hydrogen ion
- Hydron (chemistry), a.k.a. "proton" or "hydrogen"
- Isotopes of hydrogen
- Hydrogen-2 (deuterium)
- Hydrogen-3 (tritium)
- Hydrogen-4
- Hydrogen-5
Other things named "hydrogen"[edit]
- Hydrogen (horse), a champion Australian Thoroughbred racehorse
- Hydrogen (software), drum machine software