This chapter unpacks the role of civil society in relation to (in)justice in the context of urban sustainability, considering the multitude of formats, organizational structures and scales within which it operates. When justice is compromised, especially in places where civil society has a weaker presence, acts and processes of social discrimination and oppression can take a stronger hold. In addition, the term “civil society” can be misinterpreted, manipulated or co-opted toward ends that compromise justice. Certain factors can weaken the function of civil society actors, such as aspects of fund-raising and funding support, broader political environments that sanction dissent and powerful vested economic interests. The chapter examines the relationship between a healthy and functioning civil society and just sustainability, highlighting the risk of communities entering a vicious circle of weak civil society, weak social justice and weak sustainability.