Iridium-192 (symbol ¹⁹²Ir) is a radioactive isotope of iridium, with a half-life of 73.83 days. It decays by emitting beta (β) particles and gamma (γ) radiation. About 96% of ¹⁹²Ir decays occur via emission of β and γ radiation, leading to ¹⁹²Pt-192. Some of the β particles are captured by other ¹⁹²Ir nuclei, which are then converted to ¹⁹²Os. Electron capture is responsible for the remaining 4% of ¹⁹²Ir decays.

Iridium-192 is also a strong gamma ray emitter. There are seven principal energy packets produced during its disintegration process ranging from just over 0.2 to about 0.6 MeV. Iridium-192 is commonly used as a gamma ray source in industrial radiography to locate flaws in metal components. It is also used in radiotherapy as a radiation source.

Iridium-192 has accounted for the majority of cases tracked by the US Nuclear Regulatory Commission in which radioactive materials have gone missing in quantities large enough to make a dirty bomb.