Oil adsorption capacities of reduced graphene oxide (RGO) and graphite oxide (GO) were investigated and compared with commercial graphite products. Adsorption capacities were determined by measuring the adsorbed amounts using a tea bag containing the adsorbent materials. RGO and GO showed higher adsorption capacities than other graphite adsorbents. This is attributed to the increase in the interlayer spacing and consequent development of mesopore structures, resulting in a decrease in the bulk density and increase in adsorption. Expanded graphite (EG) prepared in the laboratory showed a worm-like structure and good adsorption; however, commercial milled EG showed low adsorption capacities because the pores were crushed.