Fiber reinforced polymer (FRP) composites are exceptional engineering materials for structural and automotive applications because they are strong and lightweight. Carbon and glass fibers are favoured in FRP because of their advantages. These synthetic fibers are derived from non-renewable resources and produce significant CO2 emissions. Substitute synthetic fibers with renewable fibers derived from plants, animals, and minerals to mitigate these disadvantages. Natural fibers are constrained in structural applications because of their inadequate strength and elevated water absorption. The amalgamation of natural and synthetic fibers combines sustainability with durability, rendering them appropriate for industrial applications. This paper examines the experimental and numerical buckling and post-buckling behaviour of natural fiber-reinforced functionally graded composite plates subjected to in-plane shear loads. Functionally graded hybrid (FH) composite plates comprise natural and synthetic types of hemp and carbon fibers. The matrix combines epoxy and hardener, whereas FH composites are manually fabricated by modifying the properties of natural and synthetic fibers along the thickness. The composite plates are 279 mm x 279 mm x 2.16 mm. FH composites are manufactured using stacking sequences of (0/90)4s, (−45/ + 45)4s, and (−45/ + 45/0/90)2s. The experimental buckling and post-buckling behaviour investigation uses a unique patented shear fixture. Acoustic emission experimentally identifies first-ply failure in composite plates. Abaqus software numerically forecasted buckling and first ply failure loads under simply supported boundary conditions for all plates. The linear perturbation initially assesses the buckling load, while the Tsai-hill failure criterion identifies the first ply failure load. The findings indicate that experimental and numerical results align. No stacking sequence has surpassed the first-ply failure load of the FH composite with the configuration (−45/ + 45)4S. This study identifies the structural application of natural fiber-based FH composites with cutouts of varying sizes and shapes, and this study revealed that the diamond-shaped cutout is the most effective of all the cutouts.