Solidarity is a central aspect of the Catholic social tradition and yet it is difficult to capture in a simple definition. Building upon his predecessor’s examination of solidarity, Pope Francis develops solidarity’s christological character, a previously underdeveloped aspect of Catholic social teaching. Francis’s use of place and proclamation in public ministry calls for an ethic of inclusion and encounter. Francis turns to the Incarnation as informing a theology of solidarity focused on both Jesus as model of solidarity and of lived solidarity as an encounter with Christ.