The present paper investigates the dynamic response of infinite Timoshenko beams supported by nonlinear viscoelastic foundations subjected to a mov- ing concentrated force. Nonlinear foundation is as- sumed to be cubic. The nonlinear governing equations of motion are developed by considering the effects of the shear deformable beams and the shear modu- lus of foundations at the same time. The differential equations are, respectively, solved using the Adomian decomposition method and a perturbation method in conjunction with complex Fourier transformation. An approximate closed form solution is derived in an in- tegral form based on the presented Green function and the theorem of residues, which is used for the calcu- lation of the integral. The dynamic response distribu- tion along the length of the beam is obtained from the closed form solution. The derivation process demon- strates that two methods for the dynamic response of infinite beams on nonlinear foundations with a mov- ing force give the consistent result. The numerical re- sults investigate the influences of the shear deformable beam and the shear modulus of foundations on dy- namic responses. Moreover, the influences on the dy- namic response are numerically studied for nonlinear- ity, viscoelasticity and other system parameters.