This chapter examines singlehood as both a social status and a legal category, introduces a global analytical framework, and applies the “singles question” to reveal how laws distinguish among single, partnered, and married individuals across legal systems. It defines singlehood as a complex, intersectional classification, differentiates direct and indirect discrimination, and proposes a structured method for evaluating explicit distinctions, disparate impacts, justificatory rationales, and embedded assumptions. The chapter analyzes international human rights instruments, constitutional doctrines in the United States and Taiwan, and discrete legal domains—including family law, sexual and reproductive rights, employment, public benefits, taxation, inheritance, immigration, housing, incarceration, Indigenous status, and medical decision-making—and demonstrates how marital status structures rights, obligations, and resource allocation. It shows that legal regimes alternately privilege, penalize, or ambiguously position single people while often reinforcing marital supremacy and occasionally expanding individual autonomy. Finally, the chapter calls for critical reexamination of marital classifications, urges intersectional scrutiny, and envisions legal equality that secures autonomy and equal citizenship irrespective of relationship status.