Victims of employment discrimination experience many barriers in finding redress, resulting in a general problem of underreporting. One actor has been gaining attention in this regard: the bystander to instances of discrimination. While their relevance to discrimination law has been underexplored, bystanders could play a vital role. They can report, serve as witnesses and help victims to seek redress, for instance via participating in procedures before equality bodies. However, bystanders can also experience legal barriers to intervene. Research on bystanders in discrimination law is scarce and focuses on sexual harassment and practical barriers. Instead, this project will systematically study the involvement of bystanders in employment discrimination cases and the legal barriers for intervention. To this end, social psychology and legal scholarship will be studied in order to form a theoretical framework. Then, both legal proceedings before Belgian labour courts and labour tribunals and mediation cases through the Belgian federal equality bodies will be analysed, yielding empirical insight in bystanders’ legal role in employment discrimination. Moreover, the most important actors in employment discrimination cases will be interviewed to gain in-depth data about their experiences of bystander intervention. In this way, the research will contribute to filling the theoretical gap in legal scholarship on the role of bystanders in discrimination law and formulate recommendations.