Some studies suggest that sexual and ethnic-cultural minority groups are at high risk of cyberbullying, but almost all of them focused on general cyberbullying without including specific bias-based behaviors. This study analyzed psychometric properties of a bias-based cyberbullying measure, described prevalence rates of bias-based cyberbullying in ethnic-cultural and sexual majority and minority groups, and discovered if social and emotional competencies and technology abuse predicted bias-based cyberbullying. A survey was answered by a representative sample of 2,139 adolescents from Andalusia (Spain). The measure of bias-based cyberbullying was found to have good psychometric properties. Bias-based cyberbullying victimization and being a cyberbully/victim were common among the immigrants and sexual minorities. The majority group and Roma ethnicity showed similar prevalence rates, with more perpetration than the immigrants and sexual minorities. Social and emotional competencies were protective, and technology abuse was a risk factor for bias-based cyberbullying. Implications for policy and practice are discussed.