This study evaluates the effectiveness of a Bystander Leadership™ Program (BLP) designed to mitigate gender and racial biases among faculty at a research university. The BLP workshop, grounded in comprehensive local research, provided faculty with practical intervention skills to address observed biases in academic settings. A quasi-experimental design was employed, involving tenured and tenure-track faculty (N = 253) from STEM and Social and Behavioral Science (SBS) departments. Participants were surveyed before and three months after the workshop (Intervention Group) or three months apart (Comparison Group), assessing five variables: notice bias, self-efficacy, perceived benefits of action, perceived risks of action, and actual intervention in bias incidents. The findings reveal that the Intervention Group exhibited significant increases in self-efficacy and actual interventions from pretest to posttest, unlike the Comparison Group, which showed no changes. Notably, foreign-born faculty initially had lower notice bias scores compared to U.S.-born faculty. Post-intervention, notice bias significantly increased among foreign-born faculty in the Intervention Group. Furthermore, a 60% faculty participation rate was identified as the threshold for perceiving departmental endorsement of inclusive practices. These results underscore the BLP's potential to enhance faculty's confidence and proactive engagement in addressing bias, particularly among foreign-born faculty, and highlight the importance of broad participation for fostering inclusive academic environments.