Accurately predicting the residual displacement of reinforced concrete (RC) structures after an earthquake is of great significance in post-earthquake structural performance evaluation and control. To study the residual deformation of the structure, seismic time-history responses of single degree-of-freedom (SDOF) systems with different parameters were analyzed. Based on the analytical results, simplified models for estimating the likely residual deformations of structures characterized by Takeda and Kinematic hysteretic models were proposed respectively, and the residual deformation was found to be sensitive to hysteretic characteristics, stiffness ratio of structures, peak ground acceleration (PGA), as well as maximum elasto-plastic deformation. A case study for RC single-column bridge pier was provided to illustrate the process of residual deformation calculation and post-earthquake performance evaluation by using the proposed methods. Calculation results indicate that the residual deformation of the single-column pier characterized by the Takeda model often is much larger than that of columns characterized by the Kinematic model.