<p>This study focuses on the thermal post-buckling behavior of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) quadrilateral plates, with particular emphasis on the thermal stability characteristics of four geometric configurations: rectangular plates (RP), right-angled trapezoidal plates (RTP), isosceles trapezoidal plates (ITP), and arbitrary quadrilateral plates (AQP). Employing micromechanical methods to characterize temperature-dependent nanocomposite properties, the research derives the governing equations based on first-order shear deformation theory and the minimum total potential energy principle. The generalized differential quadrature method (GDQM) is utilized to solve for thermal buckling loads, while Newton-Raphson iterative schemes combined with mapping techniques enable the standardization of irregular computational domains. Through method validation and parametric studies, the systematic influence of model parameters on the thermal buckling characteristics of FG-CNTRC quadrilateral plates is elucidated. The findings indicate that the RP exhibit the best thermal stability, with the highest critical temperature and smallest deflection, while the AQP perform the worst due to their irregular geometry. In addition, it can be observed that when no initial geometric imperfection exists, the relationship between temperature and deflection takes the form of a bifurcation curve, meaning that deflection occurs only when the temperature change reaches a critical value. In contrast, when an initial geometric imperfection is present, deflection appears as soon as a temperature change is applied.</p>