IntroductionMental illness stigma is associated with a range of negative consequences, such as reduced help-seeking for mental health problems. Since stigma affects individual, social, and structural aspects, multilevel interventions such as the Canadian programme The Working Mind have been proven to be the most effective. Given the solid evidence base for The Working Mind, it is our aim to implement and evaluate culturally adapted versions of the programme in German higher education, targeting students, employees and managers.Methods and analysisWe will evaluate the programme with regard to its effect on mental illness stigma, openness to mental health problems, willingness to seek help, and positive mental health outcomes. Further, we will investigate the programme’s effectiveness dependent on gender and personal values, various mechanisms of change, and factors facilitating and hindering implementation. The study uses a sequential explanatory mixed-methods evaluation design (QUAN → qual) that consists of three steps: (1) quasi-experimental online survey with programme participants, (2) focus groups with programme participants, and (3) qualitative interviews with programme stakeholders. The quantitative data collected in step 1 will be analysed using 2×3 analysis of variances and a parallel multiple mediation analysis. The results will inform the qualitative data to be collected in steps 2 and 3, which will be analysed using qualitative content analysis.Ethics and disseminationThe study was approved by the local Ethics Committee (Ethics Committee of University Medicine Greifswald; BB 098/23). Participants have to provide written consent before taking part in a focus group or interview. As for the online survey, participants have to give their consent by agreeing to an online data protection form before they can start completing the survey. We will publish central results and the anonymised data in an Open Access Journal. Further, the statistical code will be included as a supplement to the paper(s) documenting the results of the study.Trial registration numberDRKS00033523.