Molybdenum trioxide (MoO3)-loaded graphene (MoO3-GNS) hybrids and cuprous oxide (Cu2O)-loaded graphene (Cu2O-GNS) hybrids were successfully prepared via the hydrothermal method and one-pot coprecipitation method, respectively. Subsequently, the MoO3-GNS and Cu2O-GNS hybrids were incorporated into a polyurethane elastomer (PUE) matrix, respectively, and their effects on thermal stability, flame retardancy, and smoke suppression properties of PUE were investigated. Thermogravimetric analysis results showed that the incorporation of 2.0 wt MoO3-GNS or Cu2O-GNS hybrids efficiently improved the char yield of the PUE matrix. Moreover, the addition of MoO3-GNS or Cu2O-GNS hybrids presented excellent flame retardancy and smoke suppression properties of PUE composites, as evidenced by the obvious reduction in their heat release rate, total heat release, and smoke density. The improvement in the flame retardancy and smoke suppression properties were mainly attributed to the synergistic effect between the physical barrier effect of graphene sheets and the catalytic charring effect of MoO3 or Cu2O.