Carbon aerogels are receiving great attention in academia and industry; however, the preparation of high performance carbon aerogels is challenging. Here, we report the preparation of compressible and conductive carbon aerogels (3C aerogels) from waste paper using a general “oxidation-oven drying-carbonization” method. The 3C aerogels are lightweight (23.6 mg cm⁻³) and show good electrical conductivity (0.051 S cm⁻¹), high compressibility, superhydrophobicity/superoleophilicity and high oil absorption capacity (33–70 g g⁻¹). The 3C aerogels can also be used for the removal of free oils in water via different approaches. Moreover, the 3C aerogels can be used for efficient gravity-driven separation of surfactant-stabilized water-in-oil emulsions and simultaneous adsorption of soluble organic pollutants in the emulsions, both in the water phase and in the oil phase. The 3C aerogels may also find applications in other fields including sensors and pressure-sensitive electronics. This work opens a new avenue for designing carbon aerogels with exceptional performance for oil/water separation.