In this paper, a numerical analysis is presented using fast Lagrangian analysis of continua (FLAC) 2D for the evaluation of slope reliability. The Cholesky decomposition technique has been used to develop the 2D non-Gaussian homogeneous random field. The performance function against MSW slope failure is formulated based on the linear regression equation of factor of safety obtained using numerical package, FLAC 2D. A reliability index of MSW slopes is computed using first order reliability method (FORM). The spatially variable design parameters of MSW landfill slopes are treated as random variables. The results of the present study provide an ample understanding of the spatial variability associated with shear parameters of MSW landfill slopes. The shear stress and shear displacements along the geomembranes (GMB) interfaces are presented with and without spatial variability. The effect of correlation distance on the reliability index of MSW landfill slope is presented in the form of design charts for different mean and COV values associated with unit weight, cohesion, and friction angle of the MSW. © 2020 American Society of Civil Engineers.