Supersymmetric grand unified theories (SUSY GUTs) aim to unify all fundamental particles and interactions into a single theoretical framework by extending the Standard Model to include supersymmetry and embedding the strong, weak, and electromagnetic forces into a simple gauge group at an ultra-high unification energy scale above 1015 GeV. Key predictions include heavier supersymmetric partners to Standard Model particles, new heavy gauge bosons that mediate interactions between forces, and heavy right-handed neutrinos. Unification of gauge couplings is achieved, and SUSY GUTs provide compelling dark matter candidates. However, the richness of the theories also allows for an extensive set of experimental tests through precision measurements, proton decay, gauge boson searches, dark matter detection, and more, offering opportunities both to validate and potentially falsify these elegant attempts to describe particle physics and cosmology within a single mathematical structure.