Although it has long been thought that innocence should matter in federal habeas corpus proceedings, innocence scholarship has focused almost exclusively on claims of factual innocence—the kind of innocence that occurs when new evidence reveals that the defendant did not commit the offense for which he was convicted. The literature has largely overlooked cases where a defendant was convicted or sentenced under a statute that is unconstitutional, or a statute that does not apply to the defendant. The Supreme Court, however, has recently begun to recognize these cases as kinds of innocence and it has grounded its concern for them in innocence-related considerations. This Article highlights how the doctrine has started to treat these “legal innocence” cases as cases in which defendants are innocent, as well as the reasons why it has done so. As this Article explains, legal innocence is conceptually and inextricably linked with factual innocence; in both kinds of cases, the defendant was convicted or sentenced under a law she did not violate. These cases raise similar concerns and implicate many of the same features of our criminal law system. By recognizing the emerging category of legal innocence as a kind of innocence, this Article maps out how the existing federal habeas system can provide relief to legally innocent defendants.