Three-dimensional potential energy functions have been generated for the electronic ground state of the O2+He (X(2)II) complex using highly correlated multireference internally contacted configuration interaction (MRCI) and averaged coupled pair functional (ACPF) electronic wave functions. The complex is found to have a T-shaped equilibrium geometry with R(e)(O-2(+)... He) of 5.2363 bohr (A’ component) and 5.1601 bohr (A " component). The ACPF calculations predict the dissociation energies of 167.5 cm(-1) (A’) and 194.3 cm(-1) (A ") and the barriers to linearity of 50.9 cm(-1) (A’), and 77.7 cm(-1) (A "), respectively. The results from both MRCI and ACPF approaches have been compared. The rovibronic levels have been obtained by a variational approach which includes the rotation-vibration, electron angular momentum, and electron spin coupling effects, but neglects the nuclear spin. Vibronic states with up to six bending and two stretching quanta excited are calculated to be bound. Due to the large differences between the shapes of the A’ and A potentials, large parity splittings (more than 1 cm(-1) in excited bending levels) have been obtained. Also the influence of the vibrational excitation in the O-2(+) fragment on the large amplitude modes has been investigated.