Rate coefficients have been measured at thermal energies for the charge transfer reactions of metastable O+(2D) ions with N2 and O2. At an effective temperature of ~550 K we find k(N2)?2)¿10-10 cm3/sec and k(O2)?2)¿10-10 cm3/sec. These drift tube-mass spectrometer measurements employ the reaction He++O2 as the source of the metastable O+ ions, and evidence is presented that the ions thus produced are in the 2D state rather than the 2P state, a possible alternative, identification. The O+(2D)+N2 charge transfer rate is considerably larger than that deduced in existing photochemical model analyses of Atmosphere Explorer observations. Some of the ionospheric implications of the laboratory measurements are discussed.