We examined whether German adolescents who participated in an adapted 8-week school-based intervention, the "Identity Project," reported greater changes in heritage and global identities and perceptions of classroom cultural climate. We used a longitudinal, wait-list control design pooling eight classrooms across the school years of 2018-2019 and 2019-2020. The sample included 195 seventh graders (M[subscript age] = 12.35 years, SD = 0.79, 39% female, 83% of migration background). Findings showed moderate support for more heritage identity exploration and greater perceptions of unequal treatment and critical consciousness climate in the intervention group. There were also important differences across conditions regarding how identity and climate related to adolescent outcomes. We conclude that the "Identity Project" can be adapted and applied in other cultural contexts such as Germany. It provides a necessary space for adolescents to engage in discussions about diversity, cultural heritage, social inequities, and their relevance to one's identities.