This brief gives an initial, if incomplete, overview of the rich landscape of Catholic sisters in Sri Lanka and their noteworthy contributions to such areas as education, health, and human rights. The broad aim is to foster connections and collaborations among sisters, NGOs, civil society groups, government entities, and individuals and institutions shaping policy on the local and global stages. It provides a short history of the Catholic Church in Sri Lanka, followed by an overview of sisters’ role and impact on Sri Lankan society, from the colonial era to the present. It examines the past and present roles of sisters in the development sector. A comprehensive overview of the work of sisters would require additional research, but this overview identifies key examples and trends in sisters’ contributions to the common good in Sri Lanka. It highlights supporters and collaborators in sisters’ work, including international networks, foundations, and NGOs.