Social sustainability has often been overlooked in business process evaluation compared to the environmental and economic dimensions. However, the concept of social sustainability, which emphasizes fair and just practices towards stakeholders and society, is gaining prominence in business, yet its definition remains ambiguous, obstructing its integration into business process management. This paper investigates social sustainability indicators in current literature related to business processes. A systematic literature review reveals a diverse set of 254 indicators used to assess social sustainability, ranging from standard indicators to context-specific ones, and finds the most common indicators in the realm of employee well-being and development and human rights and labor practices. Our research highlights the need for further studies to address the challenges of defining and measuring social sustainability in the context of business processes.