Roe v. Wade grounds constitutional protections for women’s decision whether to end a pregnancy in the Due Process Clauses. But in the four decades since Roe, the U.S. Supreme Court has come to recognize the abortion right as an equality right as well as a liberty right. In this Essay, we describe some distinctive features of equality arguments for abortion rights. We then show how, over time, the Court and individual Justices have begun to employ equality arguments in analyzing the constitutionality of abortion restrictions. These arguments first appear inside of substantive due process case law, and then as claims on the Equal Protection Clause. Finally, we explain why there may be independent political significance in grounding abortion rights in equality values.