The Catholic Church is the oldest religious institution in the West and the biggest Christian denomination in Australia. Its success is partly due to its sustained efforts to supply missionaries across the globe. While the traditional missionary paradigm involved Europe-born religious workers being sent to colonies, this flow has been reversed in recent years. Increasingly, priests from the Global South are serving in Global North churches. This reversal of mission flows involves shifting from learning peripheral languages to learning center languages. This shift has important, but little understood implications in this context where language learning has moral consequences. This qualitative study examines the English language learning experiences in Australia of missionaries from Asia, Africa, and Latin America, highlighting their language socialization practices, challenges, and ideologies. Findings contribute to theorizing Catholic missionaries as a community of practice whose language learning strategies and views are partly shaped by their religious identity.