Absolute differential and integral charge transfer cross sections have been measured for 0.5, 0.85, 1.5, 2.8, and 5.0 keV O\sp+ with O\sb2 at scattering angles between 0.01\sp∘ and 3.50\sp∘ in the laboratory frame. The dependence of these cross sections upon the electronic state of the O\sp+ ion was investigated. This study was performed using a filter cell technique to derive the cross sections for both the O\sp+(\sp4S) ground state ions and the O\sp+(\sp2D, \sp2P) metastable state ions. The charge transfer cross sections involving the O\sp+(\sp2D, \sp2P) ions are significantly larger than the corresponding cross sections for the ground state ions. Previously published cross section measurements are compared to the present results for the total integral charge transfer cross sections of state-selected keV O\sp+ with O\sb2.