Abstract: The preparation of functionalized reduced graphene oxide (RGO) composite materials on various fibrous substrates has been proposed. The functionalized RGO composite fibrous materials absorb various types of oils efficiently within 20 seconds, with great absorption capacity. The maximum absorption capacity values for bicycle chain oil and used motorcycle engine oil are 880.8% and 839.1%, respectively. Simply squeezing the functionalized RGO composite materials allows the removal of the absorbed oil for reuse. The functionalized RGO composite fibrous materials have been used to efficiently separate oil/water mixture through a flowing system. Having the advantages of faster absorption rate, reusability, and low-costs, the functionalized RGO composite fibrous materials holds great potential as a superabsorbent for efficient removal and recovery of oil spills, and for separation of water/oil mixtures.