Supreme Court “companion cases” are decisions released on the exact same day that address substantially similar legal or factual matters. The list of consequential Supreme Court decisions that the Justices have resolved as part of a set of companion cases is lengthy: It includes NLRB v. Jones & Laughlin Steel Corp., Korematsu v. United States, Brown v. Board of Education, Terry v. Ohio, Roe v. Wade, Miller v. California, and Gregg v. Georgia. Although it is not surprising that important topics like civil rights and abortion generate significant amounts of litigation, the Supreme Court’s practice of conducting plenary review of multiple similar cases and issuing separate decisions resolving each one should give us pause. The Justices have a number of other procedural tools available for disposing of similar matters for which parties seek review. Options include granting certiorari for only one of the cases, vacating and remanding some of the matters, issuing at least one summary disposition, consolidating the cases, or releasing the decisions at very different times. The Court sidesteps these alternative approaches when it issues companion cases. Yet previous scholars have not devoted adequate attention to this practice as a distinct procedural mechanism, with unique characteristics that may motivate its usage. This Note fills that gap by studying some of the Court’s most famous companion cases and taxonomizing them into four categories—coordinate hedges, contested hedges, extensional reinforcements, and applicative reinforcements—based on factors including the voting behavior of the Justices and the constitutive decisions’ relationships to each other. The Note leverages that taxonomy to frame its analysis of why the Court chose to issue companion cases given all the procedural alternatives. This Note concludes by discussing how the practice of deciding certain sorts of companion cases—in which a majority of the Justices agree that they should resolve similar cases in ostensibly contradictory ways—may improve the Court’s legitimacy by accentuating its responsibility and capacity to collaboratively identify subtle distinctions between comparable cases that compel different outcomes.