A non-aqueous electrolyte solution and a lithium secondary battery including the same are disclosed herein. In some embodiments, a non-aqueous electrolyte solution includes a lithium salt, a first organic solvent that is ethylene carbonate, a second organic solvent excluding ethylene carbonate, and an oligomer represented by Formula 1 wherein a concentration of the lithium salt is 1.2 M to 3.3 M, and, wherein the first organic solvent is included in an amount of 0.1 wt % to 12 wt % based on a total weight of the non-aqueous electrolyte solution.