In the present study, a new analytical approach is developed for bending and stress analysis of angle-ply laminated composite and sandwich plates subjected to arbitrary non-uniform loads. Governing equations are derived based on the Mindlin–Reissner plate theory. For the first time, a system of three second order coupled partial differential equations is analytically solved by using power-series solution. The transverse shear stress is determined based on the three- dimensional theory of elasticity. Most of the available analytical solutions of the rectangular plates were presented for specific load and edge conditions. The proposed method can be applied for plates with arbitrary boundary conditions and various distributed loads. To demonstrate the generality and accuracy of the present method, comprehensive numerical examples are presented and compared with other available published results. The results show that the proposed solution can be applied for analysis of cross/angle-ply laminated composite and sandwich plates with various combinations of the edge conditions, orientation angle of the laminated composite plate, arbitrary non-uniform transversely distributed loads and non-uniform elastic foundation. The proposed method predicts excellent results for laminated composite plates. Also even for moderately thick sandwich plates, accuracy of the present results are in a good agreement with the exact solutions.