In this paper, an exact analysis of thermal post-buckling behavior of eccentrically stiffened functionally graded (FG) thin circular cylindrical shells subjected to thermal radial loading and surrounded by elastic foundation, is presented. Stringer and ring stiffeners are assumed to be placed on the inner surface of the FG cylinder shell and the material properties of the shell and stiffeners are assumed to be temperature dependent and continuously graded in the thickness direction. The elastic medium around the circular cylindrical shell is modeled by a two parameter elastic foundation based on the Winkler and Pasternak model. Fundamental relations and equilibrium equations are derived based on the smeared stiffeners technique and the classical theory of shells according to the von- Karman nonlinear equations. By using the Galerkin method, the thermal post-buckling response of eccentrically stiffened FG thin circular cylindrical shells are obtained. In order to validate the method, the obtained results are compared with available solutions and in continue, the effects of different parameters such as volume fraction exponent, number of stiffeners and elastic foundation parameters, on the thermal post-buckling response of eccentrically stiffened FG thin circular cylindrical shells are considered. Numerical results show that stiffeners and elastic foundation enhance the stability of the FG shells. Moreover, increasing the shell thickness, reducing the volume fraction index, increasing the number of Stringer and ring stiffeners and applying stiffer elastic foundation lead to increase the thermal post-buckling response of stiffened FG circular cylindrical shells.