The reduction of graphene oxide (GO) to graphene is typically carried out under very harsh conditions that require strong reducing agents, elevated temperatures, and long reaction times. Here we introduce a new reducing agent, lithium naphthalenide (LN: Li+ [GRAPHICS] (-))which is distinguished by the very fast (less than 10 min) and highly efficient reduction of graphene oxide, even under ambient conditions. In contrast with conventional reducing agents that yield hydrophobic reduced graphene oxide (r-GO), this new reducing agent produces r-GO with enhanced hydrophilicity and a very stable dispersion in water. As an additional advantage, the dispersibility of the resultant r-GO can be easily controlled by varying the washing conditions. This new reducing agent, LN, opens up a practical and economical route to the production of hydrophilic r-GO and broadens the applications of graphene-based materials.