伽马射线天文学是指以伽马射线研究宇宙的天文学分支。伽马射线是可穿透整个宇宙的电磁波中最高能量的波段，也是电磁波谱中波长最短的部分。

伽马射线可由太空中的超新星、正电子湮灭、黑洞形成、甚至是放射衰变产生。例如超新星SN 1987A就发射了来自超新星爆炸的放射性产物钴56释放的伽马射线。大多数天体释放的伽马射线一般认为并非来自放射衰变，而是和X射线天文学一样来自加速的电子、电子和正电子作用（但因为能量较高而产生伽马射线）。

Gamma-ray astronomy is the astronomical observation of gamma rays, the most energetic form of electromagnetic radiation, with photon energies above 100 keV. Radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy.

Gamma rays in the MeV range are generated in solar flares (and even in the Earth's atmosphere), but gamma rays in the GeV range do not originate in the Solar System and are important in the study of extrasolar, and especially extra-galactic astronomy. The mechanisms emitting gamma rays are diverse, mostly identical with those emitting X-rays but at higher energies, including electron-positron annihilation, the Inverse Compton Effect, and in some cases also the decay of radioactive material (gamma decay) in space reflecting extreme events such as supernovae and hypernovae, and the behaviour of matter under extreme conditions, as in pulsars and blazars. The highest photon energies measured to date are in the TeV range, the record being held by the Crab Pulsar in 2004, yielding photons with as much as 80 TeV.