<p>The maximum transverse deflection responses of a multilayer sandwich panel (flat and curved) with cutouts under uniformly distributed load have been investigated in this work using a mathematical model. The mathematical model is developed using higher-order shear deformation theory combined with the finite element method. The governing equation for the static analysis is obtained by utilizing the variational principle. The desired deformation responses are computed by a MATLAB-based computer program. Before the implementation of the proposed model for the bending analysis of sandwich panels, the necessary accuracy test of the developed numerical model is conducted by comparing the results with the available published data. Additionally, a flat sandwich composite panel with different face sheet layers has been fabricated using an in-house developed fabrication facility. The experimental bending test has been performed using an experimental test setup available at NIT Patna. The experimental responses are now being compared to the numerical responses. After the successful validation study, the developed model has been used to investigate the effect of different cutout parameters such as size, shape, and position, as well as geometrical, material, and boundary conditions on the deflection behavior of a sandwich composite flat/shell panel. Lastly, the observation of the obtained response is discussed in detail.</p>