Recently, nanostructure-based gas sensors have drawn huge attention in this industrial era for environmental monitoring. We have performed DFT computations using B3LYP functional with6–31G Gaussian basis set to study the interaction of O3 molecules with B12N12, Al12N12, Ga12N12, AlB11N12, and GaB11N12 nanocages. To explore the sensing behavior, we have investigated structural properties, thermodynamic properties, electronic properties, dipole moment, and NBO charge transfer. The quantum theory of atoms in molecules (QTAIM) analysis displays that the interaction of O3 molecules with group-III nitride nanocages is a closed shell (non-covalent) type. The total density of state (DOS) graph shows that after adsorption the HOMO-LUMO band gap reduces in the significant range i.e. adsorption has a noteworthy influence on electronic properties. Therefore, AlB11N12, GaB11N12, and Al12N12 could be very promising in the field of sensing O3 molecules.