The non-frictional contact between two semi-infinite elastic bodies, one of which has a wavy surface, is considered for the case of interface gaps filled with a compressible barotropic liquid. The contact problem formulated is reduced to a singular integral equation (SIE) with the Hilbert kernel, which is transformed into a SIE with the Cauchy kernel for a derivative of a height of the gaps. A system of transcendental equations for a width of the gaps and a pressure of the liquid is obtained from the condition of boundedness of the SIE solution at the integration interval ends and the equation of state of a compressible barotropic liquid, and then it is solved numerically. The dependences of the width and shape of the gaps, the pressure of the liquid, the average normal displacement and contact compliance of the bodies on the applied load and bulk modulus of the liquid are analyzed.