A gel electrolyte for a rechargeable lithium battery, comprising: a gel polymer comprising a repeating unit derived from a first monomer represented by Chemical Formula 1; a non-aqueous organic solvent; a lithium salt; and an additive comprising a compound selected from the group consisting of compounds represented by Chemical Formula 10, compounds represented by Chemical Formula 11, derivatives thereof, and combinations thereof, present in an amount of about 0.1 wt% to about 10 wt% based on the total weight of the gel electrolyte: Chemical Formula 1 A-L-E wherein, in Chemical Formula 1: L is a residual group of a polyester polyol, and each of A and E is independently selected from the group consisting of moieties represented by Chemical Formulae 2 to 4 and 6 to 9: wherein, in Chemical Formulae 2 to 4 and 6 to 9: each of R 1 to R 8 is independently selected from the group consisting of hydrogen, substituted and unsubstituted C1 to C10 aliphatic organic groups, and substituted and unsubstituted C6 to C20 aromatic organic groups, wherein, in Chemical Formulae 10 and 11: each of R9 to R 12 is independently selected from the group consisting of hydrogen, halogens, substituted and unsubstituted C1 to C10 alkyl groups, substituted and unsubstituted C1 to C10 alkoxy groups, and substituted and unsubstituted C2 to C10 alkenyl groups. a gel polymer comprising a repeating unit derived from a first monomer represented by Chemical Formula 1; a non-aqueous organic solvent; a lithium salt; and an additive comprising a compound selected from the group consisting of compounds represented by Chemical Formula 10, compounds represented by Chemical Formula 11, derivatives thereof, and combinations thereof, present in an amount of about 0.1 wt% to about 10 wt% based on the total weight of the gel electrolyte: Chemical Formula 1 A-L-E wherein, in Chemical Formula 1: L is a residual group of a polyester polyol, and each of A and E is independently selected from the group consisting of moieties represented by Chemical Formulae 2 to 4 and 6 to 9: wherein, in Chemical Formulae 2 to 4 and 6 to 9: each of R 1 to R 8 is independently selected from the group consisting of hydrogen, substituted and unsubstituted C1 to C10 aliphatic organic groups, and substituted and unsubstituted C6 to C20 aromatic organic groups, wherein, in Chemical Formulae 10 and 11: each of R9 to R 12 is independently selected from the group consisting of hydrogen, halogens, substituted and unsubstituted C1 to C10 alkyl groups, substituted and unsubstituted C1 to C10 alkoxy groups, and substituted and unsubstituted C2 to C10 alkenyl groups. L is a residual group of a polyester polyol, and each of A and E is independently selected from the group consisting of moieties represented by Chemical Formulae 2 to 4 and 6 to 9: each of R 1 to R 8 is independently selected from the group consisting of hydrogen, substituted and unsubstituted C1 to C10 aliphatic organic groups, and substituted and unsubstituted C6 to C20 aromatic organic groups, each of R9 to R 12 is independently selected from the group consisting of hydrogen, halogens, substituted and unsubstituted C1 to C10 alkyl groups, substituted and unsubstituted C1 to C10 alkoxy groups, and substituted and unsubstituted C2 to C10 alkenyl groups.