In this study, solutions to the dynamic response of multi-layer soil under progressive waves are presented. Analytical solutions for a soil layer developed by the author are extended to multi-layers considering all the inertial terms. Problem is also solved with finite elements and numerical results are verified with the analytical counterparts. Dynamic response is evaluated in terms of displacement, pore pressure and stress variations in the layers. The effect of surface layer and underlying granular layers on the response is presented for various non-dimensional parameters. Applicability of inertial terms in the equations is also determined. Parametric results indicate that thickness and permeability of the surface layer as well as the frequency of the wave significantly affect the response. It is determined that the need to include inertial terms in the equations is controlled by how the flow speed changes between the layers depending on relative ratios of respective physical parameters.