It has long been recognized that the Indian subcontinent is home to two markedly different systems of kinship that broadly correspond to prominent linguistic and geographical divisions in the region: those of the Indo-Āryan North and the Dravidian South. Moreover, scholars have widely agreed that the most distinctive feature of Dravidian kinship is the widespread practice of cross-cousin marriage in its various forms. In the Indo-Āryan North, by contrast, a man is generally forbidden from marrying a woman to whom he is biologically related in any way within a fairly large number of generations. Nevertheless, by the close of the first millennium CE, Brāhmaṇa intellectuals throughout India shared in common both a canon of scriptural sources and a complex tradition of jurisprudence known as Dharmaśāstra. Hence, this raises the question: How did classical Brāhmaṇical jurists of the North and the South deal with the controversial issue of cross-cousin marriage? It is this question that this article aims to address in comprehensive detail. In particular, it will trace the treatment of cross-cousin marriage within Dharmaśāstra from the earliest texts of the tradition up to the two earliest and most prominent juridical defenses of the custom, composed in the thirteenth and fourteenth centuries. It will then conclude by drawing attention to a rare case where a particular Dharmaśāstra work can be seen to have influenced the marriage practices in a particular region of South India in the premodern past.