Functionalized graphene manufacturing usually consists of two consecutive steps of graphene production and functionalization, which are mainly accompanied with several reaction routes and waste generation. Herein, we demonstrated a facile one-step method for the simultaneous exfoliation of graphite and surface functionalization of the resulting graphene using electrochemical approach. We showed that presence of a water soluble acrylate monomer e.g., n-butyl acrylate in an ammonium sulphate electrolyte solution can functionalize graphene through in situ polymerized n-butyl acrylate monomers during electrochemical exfoliation. Overall yield for electrochemically synthesized and functionalized graphene nanosheets was ~25% with respect to as-received natural graphite, which contain at least 80% few-layer nanosheets with a thickness less than 7 nm. It was found that these electrochemically produced and functionalized nanosheets can serve as a potential reinforcing agent in fabrication of thermoset and thermoplastic-elastomer polymer nanocomposites with enhanced mechanical performance.