Peer assessment training was motivated, developed and evaluated to address fairness in higher education group learning. Team-centric pedagogies, such as team-based learning have been shown to improve engagement and learning outcomes. For many instructors using teams, peer assessments are integral for monitoring team performance and ensuring accountability. However, students often view the peer assessment process as unfair due to the potential for biased ratings or perceived lack of peer qualification. Peer assessment fairness training was developed by combining lessons learned from focus groups with instructors, students and learning experts with bias-reducing techniques found to be effective in other settings. The resulting training underwent a summative evaluation across multiple classrooms. Results indicated that students had higher perceptions of fairness in their peer assessments after training. Students were also more confident in their and their peers' fair rating skills. These results indicate that classroom training could be used to increase peer assessment fairness. Fairer peer assessment provides enhanced access to active and team learning benefits to a broader range of students, potentially impacting the retention of a more diverse population of practitioners in the field.