The concept of professional learning, with the principal as lead learner working towards the institutional goal of social justice, is the focus of this descriptive qualitative study. The purpose was to examine the actions and behaviours of US rural principals as they demonstrate professional learning to ensure social justice for marginalised students. Multiple iterations of coding the field notes and interview data resulted in the following themes: Professional Learning in a Social Context; Professional Learning in a Culture of Care; and Professional Learning for Positive Change. This study confirmed that social justice practices for marginalised children may be taught by leading through informal professional learning and is accomplished through learning in a social context for others to observe and hear, development of a culture of care, and focus on positive change in beliefs and attitudes. Professional learning that is embedded in the daily work of schools is the most viable strategy for rural teachers to incorporate social justice practices in their daily work. One implication from these findings is that principals must first become social justice role models and competently practice socially just behaviours themselves. Based on findings from this study, a model for professional learning is offered.