Cultural heterogenisation of classrooms and existing achievement gaps have led to an acknowledgement of the need to develop teachers' intercultural competencies. A growth mindset (a belief that intelligence, personality and other such qualities can be cultivated) predicts positive intergroup attitudes and reduces stereotyping, but has not been researched as an aspect of teachers' intercultural competence. This study analyses the role of growth mindset in shaping three aspects relevant to teachers' intercultural competencies: process versus trait orientation to students, diversity beliefs and orientation to social justice and equity. Fifteen Finnish comprehensive schoolteachers were interviewed. Significant differences were found between teachers with fixed and growth mindsets. Teachers with a growth mindset were more likely to hold polyculturalist beliefs about the interconnectedness and changeability of cultures, and to recognise and combat issues of social injustice and inequity. Teachers with a fixed mindset made trait-focused interpretations of their students and did not easily recognise problems of social justice in school or in society. These results encourage us to suggest that a growth mindset is a construct with a lot of potential to introduce novel approaches to multi/intercultural and social justice teacher education, but more research is needed. The implications of the findings for teacher education and further research are discussed.