Functionally graded (FG) nanocomposites have widespread applications in spacecraft, rockets, the automotive sector, and green buildings, including energy conservation and emission reduction, environmental friendliness, and improved building performance. In this study, the concept of nanocomposites (NCs), their formation history and processes, production methods, advantages, and applications in industries requiring advanced technology are presented. After defining the thermo-mechanical properties of functionally graded (FG) nanocomposite plies and multilayer plates, the buckling behaviour is discussed. A solution example for the buckling problem of FG carbon nanotube (CNT)- reinforced polymer-based multilayer plates under biaxial compressive load is presented within the framework of the shear deformation plate theory (SDPT). Numerical analyses are carried out for the minimum values ​​of biaxial buckling load (BBL) for different volume fraction ratios and different CNT shapes in the plies and layer alignment. The analysis clearly shows that incorrect or suboptimal laminate designs can cause significant structural efficiency losses, especially in thin-walled or shell-type components where buckling is the primary failure mode.