An electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the electrolyte, the electrolyte including a non-aqueous organic solvent; a lithium salt; and an additive, wherein the additive includes a compound represented by Chemical Formula 1: wherein, in Chemical Formula 1, R is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C3 to C10 cycloalkenyl group, or a substituted or unsubstituted C6 to C20 aryl group, and n is an integer of 1 to 3.