This guest editorial has three aims: First, the highlights of the 24th Workshop on Aggression are summarized; second some theoretical and empirical insights regarding bullying, diversity, and migration are outlined; and third, the four manuscripts accepted for publication in this thematic section of IJDS are shortly introduced. The 24th Workshop on Aggression 2019 was hosted by Norwegian Centre for Learning Environment and Behavioural Research in Education, University of Stavanger, Norway. The conference focused on International Perspectives on Bullying, Segregation, and Inclusion. After 40 years of research on bullying, we know much about motives, risks for, and consequences of bullying behaviour. However, there is still need for research due to influences of (increasing) migration, new forms of aggressive behavior etc. This is especially true for ethnic and/or other types of stigma, identity-based or bias based bullying (Mulway, Hoffman. Gönültas, Hope, & Cooper, 2018), cyberbullying, motives, and con