This study examines the free vibration and buckling behavior of functionally graded (FG) sandwich beams supported by a Winkler-Pasternak elastic foundation, utilizing a quasi-3D deformation theory. The material properties of the FG sandwich beams are modeled to vary continuously through the thickness according to a power-law distribution. Using Hamilton’s principle, the governing equations of motion are derived. Analytical solutions are obtained for simply supported FG sandwich beams with homogeneous cores by employing Navier’s method. The accuracy of the proposed model is demonstrated by comparing the current results with the higher-order deformation theories-based solutions available in literature. A compre-hensive parametric study is also carried out to explore the effect of the skin-core-skin thickness ratio, the power-law index, beam span-to-depth ratio, normal strain, core material, and elastic foundation on fundamental natural frequencies and critical buckling loads.