Reinforced concrete (RC) jacketing is nowadays one of the most common techniques adopted for strengthening of existing RC columns. It is used to increase load-carrying capacity and ductility of weak existing members by means of a simple and cheap method. In this paper, a finite element model of RC columns strengthened with RC jacket under eccentric loading were developed using two-dimensional shell element model. To simulate the interaction between old and new concrete, the adhesive layer was modeled using cohesive surface-to-surface interaction model. Results of the finite element (FE) model are verified by comparing them with experimental work available in the literature. The result of the FE model showed good agreement with experimental results, as they were able to predict the behavior of the strengthened columns and the modes of failure with high accuracy. A parametric study was conducted to study the effect of assuming perfect bond at the interface between old and new concrete on the behavior of strengthened columns.