Graphene-based materials have attracted considerable attentions due to their unique properties. However, the negligible and uncontrollable band gap of graphene greatly limits its further applications. Hydrogenation is a facile and well-studied chemical modification technique to widen the band gap of graphene with a high tunability. Herein, we reveal the structure, properties, and forming mechanism of hydrogenated graphene, summarize recent advances in its synthesis and engineering in terms of plasma hydrogenation, thermal cracking, Birch reduction, and electrochemical reduction, and discuss its potential applications in hydrogen storage, electronics, biomedicines, etc. In the last part, we further outline the challenges and future research directions for highly efficient graphene hydrogenation. © 2020 Elsevier B.V.