•We show that the bending moments are reduced but the deflections are increased by increasing the temperature.•We show that nonlinear bending behaviors of CNTRC panels are significantly influenced by the CNT volume fraction.•We show that nonlinear bending behaviors of CNTRC panels are significantly influenced by the foundation stiffness.•Nonlinear bending behaviors of CNTRC panels are significantly influenced by the character of inplane boundary conditions. Nonlinear bending analysis is presented for nanocomposite cylindrical panels subjected to a transverse uniform or sinusoidal load resting on elastic foundations in thermal environments. Carbon nanotubes are used to reinforce the cylindrical panels in two distinguished patterns, namely, uniformly distributed (UD) and functionally graded (FG) reinforcements. The material properties of CNTRCs are assumed to be temperature-dependent and are estimated by a micromechanical model. The governing equations of the panel are derived based on a higher-order shear deformation theory with a von Kármán-type of kinematic nonlinearity and are solved by a two-step perturbation technique. The nonlinear bending behaviors of the CNTRC panels with different CNT volume fraction distributions, foundation stiffnesses, temperature rise, and the character of in-plane boundary conditions are studied in details.