Drawing on original fieldwork, other primary and secondary sources, we assess whether widespread sexual violence during Myanmar’s 2017 military operations against Rohingya communities was policy (ordered or authorized by commanders) or practice (driven from below and tolerated by commanders). We argue that sexual violence was authorized as a policy based on (1) the regime’s long-standing ideological exclusion of the Rohingya from citizenship and its record of demographic engineering to limit their reproduction, (2) the context of ethnic cleansing and commanders’ effective control of forces, (3) evidence that the military engages in a distinct pattern of sexual violence against the Rohingya, including the targeting of reproductive capacity, and (4) a record of long-standing and ongoing impunity for conflict-related sexual violence, including against the Rohingya. Our analysis contributes to scholarly understanding of the conditions under which sexual violence is authorized as policy and those under which ideology prescribes or legitimates specific patterns of violence, including ethnic cleansing. It is also timely for efforts to prosecute and prevent conflict-related sexual violence.