We argue that teacher autonomy should be conceptualised differently from its current form, that confines teacher autonomy to the individual, or to freedom from control. Here, we investigate the role of trust concerning teachers' perceptions of their own autonomy, embedded in differing contexts and relations. To display contextual variations, we study qualitatively a sample of Canadian and Finnish upper-secondary school mathematics teachers. Our findings reveal that trust plays a decisive role in whether teachers feel autonomous or not, and that trust plays a central role in relationships teachers have at work. Furthermore, trust is articulated differently according to the teachers' context. Based on our findings, we argue that a reconceptualisation of teacher autonomy is needed. A relational conceptualisation of teacher autonomy, highlights its inherent relationality and contextual sensitivity, provides new insight into the teachers' work, and supports more empowering ways for teachers to exert a proactive influence on their autonomy.