Purpose <p>This work presents the development and systematic validation of a high-efficiency finite element model designed for the free vibration analysis of simply supported laminated composite plates. The formulation prioritizes computational economy without compromising predictive fidelity, explicitly integrating transverse shear deformation to ensure physically realistic dynamic responses.</p> Method <p>A four-variable non-polynomial shear deformation theory (NPSDT) is implemented, free from shear correction factors and inherently satisfying zero transverse shear stress at plate surfaces. Two element topologies are compared: four-node (Q4) and eight-node (Q8) rectangular elements (4 DOF/node), under parametric variation of orthotropy ratio (E₁/E₂ = 3–40), span-to-thickness ratio (a/h = 2–100), and number of layers (<i>n</i> = 1–10), using material data from Noor.</p> Results <p>The Q4 element yields identical natural frequencies to Q8, while reducing global matrix size by 66% (Q4: 4.0 × 10⁶ DOFs vs. Q8: 12.0 × 10⁶ for <i>n</i> = 10³). Frequencies increase with E₁/E₂, a/h, and n, with saturation observed beyond a/h ≈ 20 and <i>n</i> ≈ 10, consistent with Kirchhoff–Love behavior and some literature.</p> Conclusion <p>The Q4-NPSDT formulation offers high accuracy with minimal computational overhead, making it ideal for large-scale or iterative dynamic design of composite structures. Limitations (simply supported, linear elastic, no experimental validation) suggest future extensions to complex boundaries, nonlinearities, and data-driven optimization.</p>