This paper deals with the analytical and numerical global buckling analysis of rectangular sandwich plates consisting of aluminum facesheets and AlSi10Mg lattice cores. In the study, five different isotropic and orthotropic lattice core models are designed according to additive manufacturing production conditions. Analytical studies were carried out using Kirchoff plate theory (CLPT), first-order shear deformation theory (FSDT), and Reddy’s third order shear deformation theory (TSDT) coded on MATLAB and numerically in Abaqus. In the theories, the Navier solution is derived for sandwich plates based on simply supported boundary conditions at all edges. In the numerical analyses, validated homogenized lattice structures models were used to avoid excessive numbers of elements and to save computational time. The parametric effects of side-to-thickness ratio, and different designed core cells on global buckling load, in-plane stresses, displacements and transverse shear stresses are investigated. As a result of comparing the analytical results with the Abaqus model, a good agreement is obtained, and it is understood that FSDT and TSDT plate theories can be used within certain size limits for global buckling analysis of lattice core sandwich structures as they provide less computational effort and time-saving.