162 Background: The US is a diverse country with 13.6% of the population identifying as African-American, 19.1% as Hispanic or Latino, and 50.4% female according to the most recent US Census. Per demographic data from the American Society for Radiation Oncology (ASTRO) (the largest US organization of radiation oncologists), 28% of radiation oncologist members identify as female, 4% as African-American race, and 4% as Hispanic/Latino ethnicity; additional data has indicated the rate of URM radiation oncologists in US comprehensive cancer cents to be 5%. This data objectively indicates that females and URMs are underrepresented in the field of radiation oncology compared with the gender and racial/ethnic diversity of the US population. There is minimal data regarding promotion rates in academic radiation oncology, with virtually no data focusing on promotion rates among females and URMs. The primary objective of this study was to assess the relationships between gender and URM status in academic promotion of radiation oncology faculty. Methods: A database consisting of radiation oncologists from 51 National Cancer Institute-designated Comprehensive Cancer Centers from 2019 was accessed in September 2023 to assess academic promotion in a four-year timespan. Data regarding the gender, graduation year, institution, URM identification, and professional rank of radiation oncologists ranked as junior faculty was collected. URM was defined as African-American race and/or Hispanic ethnicity and was collected via self-described internet depictions, interviews, and facial recognition as previously described (PMID 30996695). Junior faculty status was defined as instructor/assistant professor. An online search was then conducted to identify the 2023 academic rank of previously identified faculty, focusing on promotion status from junior to senior faculty or from associate professor to full professor. Regression analysis was performed using a generalized linear mixed model to assess the impact of gender and URM status on promotion, with statistical significance defined as p < 0.05. Results: In an analysis of 554 radiation oncologists comprised of 203 women (36.7%) and 21 URMs (3.8%), 338 (61%) received promotions. Analysis revealed that neither female gender (odds ratio 1.02, 95% confidence interval, 0.68 – 1.52; p -value 0.94) nor URM status (odds ratio 0.57, 95% confidence interval 0.19 – 1.71; p -value 0.32) was significantly associated with promotion. Conclusions: These findings indicate that radiation oncologist gender and URM status may not be associated with academic promotion. However, given the small URM sample size and odds ratio of 0.57, it is possible that this study may be underpowered to adequately assess URM status on promotion. Further studies involving longer time intervals will provide much needed additional data regarding academic promotion.