This chapter presents a computational finite element (FE) modeling approach for analyzing the mechanical properties of graphene nanoplatelets reinforced natural rubber (GPL/NR) nanocomposite under small deformation. Moreover, the presented results and trends are converged using two analytical models, namely, rules of mixture (ROM) and Halpin–Tsai(HT), as well as existing experimental findings. By means of cubic representative volume element (RVE) with periodic boundary conditions considering two distinct GPL distributions, a three-dimensional FE model is developed to examine the micromechanical properties of nanocomposites. This chapter examines the effect of volume fraction, aspect ratio, and nanofillers distribution on the mechanical properties of the proposed composite. It is significantly observed that due to addition of a small volume fraction of GPL to rubber, the stiffness of nanocomposites is improved while decreasing by increasing its aspect ratio. Randomly dispersed GPL is also found to be less stiff than aligned GPL. This work presented in this chapter will provide assistance to readers in conceptualizing the behavior of rubber nanocomposites instead of incurring the costs of experimentation.