Functionally graded porous plates (FGPPs) have gained considerable attention in advanced structural applications due to their high stiffness-to-weight ratio and tunable mechanical properties. In this study, an advanced flexural analysis of functionally graded porous plates is presented, focusing on the influence of different porosity distribution models through a comprehensive parametric investigation. The material properties of the plate are assumed to vary continuously along the thickness direction according to a power-law function, while porosity is introduced using several commonly adopted distributions, including uniform, symmetric, and asymmetric patterns. An efficient higher-order plate theory is employed to accurately capture the effects of transverse shear deformation without the need for shear correction factors. The governing equations are derived from Hamilton’s principle and solved using the finite element method to obtain the transverse deflections under mechanical loading. The accuracy of the proposed formulation is verified through comparison with available results from the literature and benchmark solutions. A detailed parametric study is conducted to examine the effects of porosity coefficient, gradation index, plate aspect ratio, thickness ratio, and boundary conditions on the flexural behavior of the plates. The results reveal that both the magnitude and distribution of porosity significantly influence the bending stiffness and deflection response of functionally graded plates. In particular, asymmetric porosity distributions are shown to induce notable changes in stress profiles compared to symmetric and uniform models. The findings of this work provide valuable insights for the optimal design of lightweight porous FGM structures and offer reliable reference data for future analytical and numerical investigations in advanced plate mechanics.