Linguistic and cultural diversity is a common feature of Canadian and U.S. postsecondary demographics, yet Canada's official bilingualism has created unique demands and opportunities for bilingual WAC/WID development and instruction. This article first situates bi- and multilingual WID needs and practices in Canadian academia within the country's broader demographic, historical, and legal contexts. It then illustrates the challenges of bilingual English-French WID by means of a case study, and suggests ways to address these challenges by describing a course in academic biliteracy recently developed within a modern language department. These examples serve to underscore the potential of cross-pollinating WAC/WID with modern languages, bilingual education, and translation, and help to anchor a more theoretical discussion on how the biliteracy and translanguaging approach to WAC/WID that is proposed here relates to the translingual approach that has been advocated in U.S. composition.