In the present study, the effects of graphene nanoplatelets (GNPs) contents on the axial and lateral buckling behavior of carbon/aramid hybrid-woven epoxy nanocomposites were investigated. The composite plates were fabricated with different concentrations of GNPs (0.1, 0.25, and 0.5 wt%) by vacuum-assisted hand lay-up method. The addition of GNPs has resulted in enhancement in axial and lateral critical buckling loads. The maximum enhancement in both axial and lateral critical buckling reached with 0.1 wt% GNPs addition. These percent enhancement values in axial critical buckling loads were 25.7%, 5.2%, and, 14% with fixed-fixed, fixed-free, and free-free boundary conditions, respectively. For lateral critical buckling load, the maximum enhancement was recorded as 20.6% compared to the pure control sample. Also, with the further addition of GNPs, critical buckling loads decreased, which is interpreted because of the agglomeration of GNPs. The failure surfaces were then observed with scanning electron microscopy to examine the link between the buckling behavior and failure types of the composite samples.