This review systematically analyzes recent studies on proton and neutron irradiation in Ga ₂ O ₃ , spanning a wide energy range (keV-GeV) and including less commonly discussed polymorphs such as α-, γ-, κ-, and δ-Ga ₂ O ₃ alongside the β-phase. While prior works often focus narrowly on specific structures, this review aims to provide a broader comparative perspective across polymorphs, irradiation types, and defect formation pathways, with particular emphasis on their impact on device-level characteristics such as breakdown voltage and leakage current. Proton irradiation typically induces Ga-vacancy-related compensating defects, with CRR values ranging from 100 to 400 cm ^-1 . In contrast, neutron irradiation, although less ionizing, can lead to comparable or even greater carrier compensation. The response of doped and heterostructured systems is critically assessed, highlighting both vulnerabilities and mitigation strategies, including annealing and co-doping. The novelty of this review lies in its polymorph-specific and irradiation-type-comparative perspective, providing unified benchmarks (CRR, trap spectra, annealing pathways) that enable direct cross-study comparisons and guide the design of radiation-tolerant Ga ₂ O ₃ -based electronics.