The present study deals with the evaluation of vertical and lateral static stiffness of a smooth rigid irregularly shaped foundation using a semi analytical approach resting on multi-layered non-homogeneous soil. Currently, empirical equations are used for evaluating lateral and vertical static stiffness and these equations are applicable for regular shaped foundations on uniform soil with stiffness of the foundation ranging from flexible to intermediate rigidity. Hence, in the present work, a methodology is proposed to evaluate static stiffness for arbitrary shaped foundations founded on layered soil. These types of arbitrary shaped foundations are generally provided for large nuclear safety related structures. In the present work, a real site data of geotechnical investigation of Uttar Pradesh site is considered. Unlike previous studies, epistemic uncertainty of soil is also incorporated along with the heterogeneity of soil to take care of the uncertainty in the estimated values of the soil properties. Flexibility approach is used which comprises of formulating the flexibility matrix of the soil foundation interface utilizing the point load solutions on an elastic half-space for vertical and horizontal degree of freedom. Three-dimensional finite element analysis of the soil and foundation domain is carried out to validate the stiffness obtained from the present approach and the values are found in agreement with each other. After validation of the present approach, the stiffness’s of arbitrary shaped surface foundation resting on layered soil are reported as mean, mean + Standard. Deviation (S.D.) and mean – Standard. Deviation (S.D.) values considering uncertainty in soil properties.