Highly basic MgO modified nanoporous carbon composites have been fabricated via a facile evaporation induced self-assembly (EISA) strategy and a subsequent heat treatment. Especially, the as-obtained composites intrinsically possess strong basicity without the need of post-functionalization. Highly crystalline cubic-phase MgO nanoparticles uniformly disperse in the porous carbon matrix and the composites have large surface areas (1138 m² g⁻¹ at maximum) and pore volumes (0.616 cm³ g⁻¹ at maximum). Methanol vapor adsorption is investigated systematically on the C–MgO composites. The largest methanol adsorption capacity is up to 11.90 mmol g⁻¹ and this result is very outstanding as compared to those of previously reported porous materials. The methanol isotherms exhibit an overall organophilic nature and the Langmuir model is applied to describe the methanol adsorption behavior on the C–MgO composites. Furthermore, the C–MgO-15.4% sample with the highest adsorption capacity exhibits high selectivity for methanol/water separation at 298 K, indicating that the C–MgO-15.4% sample could be a potential adsorbent material for methanol adsorption and separation.