The present invention relates to a separator for a lithium secondary battery, and a lithium secondary battery including the same. The separator includes a porous substrate, and a coating layer on at least one surface of the porous substrate, wherein the coating layer includes a (meth)acrylic copolymer including a first structural unit derived from (meth)acrylamide, a second structural unit derived from (meth)acrylonitrile, and a third structural unit including at least one of structural units derived from (meth)acrylamidosulfonic acid, a (meth)acrylamidosulfonic acid salt, or a combination thereof; inorganic particles; and an organic filler; wherein the organic filler is included in an amount of 0.1 to 50 wt % based on a total amount of the organic filler and the inorganic particles.