Graphene and graphene oxide are widely applied as successful sorbent materials for various compounds obtained from biosamples and surface water samples. Therefore, they are suitable for future use in numerous biomedical and environmental applications. Moreover, their functionalization with magnetic nanoparticles can lead to magnetic sorbents, thus allowing convenient sample treatment via magnetic separation. To date, a plethora of graphene and graphene oxide materials have been synthesized and successfully employed for solid-phase extraction of organic compounds from environmental and biological samples. The unique properties of these materials enrich the analytical toolbox available for the analysis of various organic compounds in various matrices and make them precise and valuable means for handling analytical and environmental issues. This Special Issue was supported by the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society. Eleven manuscripts, namely seven research articles, three reviews and one communication are included in this SI.