Dataset of δ18O of atmospheric O2 and δ(O2/N2) data from the EPICA Dome C ice core from the deepest 200 m of stratified ice (294 depth levels), hence covering the past 600 to 800 ka. The EPICA Dome C ice core has been drilled in Antarctica (-75.1°S; 123.395°E; 3233 m elevation) between 1996 and 2004. This age range has been covered by previous studies (Bouchet et al., 2023, Clim. Past), but we provide new data of higher spatial and, thus, temporal resolution (0.7 ka on average). COVERAGE: Latitude: -75.102, Longitude: 123.395; Minimum Depth: 3015.06 m, Maximum Depth: 3188.18 m PARAMETERS: Depth (m), AICC2023 Ice Age (ka BP), AICC2023 Air Age (ka BP), δ18Oatm (‰), δ(O2/N2) (‰) SIZE: 294 δ18Oatm data points; 291 δ(O2/N2) datapoints________________________________________________________________________________________ Dataset of CH4 data from the EPICA Dome C ice core across the MIS19 (~770 and ~800 ka BP). The EPICA Dome C ice core has been drilled in Antarctica (-75.1°S; 123.395°E; 3233 m elevation) between 1996 and 2004. This age range has been covered by previous studies (Loulergue et al. 2008, Nature), but we provide new discrete measurements refining the variability across MIS19. COVERAGE: Latitude: -75.102, Longitude: 123.395; Minimum Depth: 3168.04 m, Maximum Depth: 3183.59 m PARAMETERS: Depth (m), AICC2023 Air Age (ka BP), CH4 (ppbv) SIZE: 28 datapoints Supplement to Klüssendorf, A., Landais, A., Casado, M., Guilluy, H., Parrenin, F., Capron, E., Fischer, H., Schmitt, J., Michel, E., Prié, F., Brugère, E., Teste, G., Salaün, S.: Orbitally Dating the Deepest Layers of EPICA Dome C: Reconciling Marine Sediment and Ice Cores. Submitted to Nature Geoscience.