Cancer incidence is expected to increase in coming decades, disproportionately so among minoritized communities. Racially and ethnically concordant care is essential to addressing disparities in cancer outcomes within at-risk groups. Here, we assess trends in racial and ethnic representation of medical students (MS), general surgery (GS) residents, and complex general surgical oncology (CGSO) fellows. This is a retrospective review of data from the American Association of Medical Colleges and the Accreditation Council of Medical Education (ACGME) from 2015 to 2020. Self-reported race and ethnicity was obtained for MS, GS, and CGSO trainees. Race and ethnicity proportions were compared with respective representation in the 2020 US Census. Mann-Kendall, Wilcoxon rank sum, and linear regression were used to assess trends, as appropriate. A total of 316,448 MS applicants, 128,729 MS matriculants, 27,574 GS applicants, 46,927 active GS residents, 710 CGSO applicants, and 659 active CGSO fellows were included. With every progressive stage in training, there was a smaller proportion of URM active trainees than applicants. Further, URM, Hispanic/Latino, and Black/African American trainees were significantly underrepresented compared with 2020 Census data. While the proportion of White CGSO fellows increased over time (54.5-69.2%, p = 0.009), the proportion of Black/African American and Hispanic/Latino (URM) CGSO fellows did not significantly change over the study period, though URM representation was lower in 2020 as compared with 2015. From 2015 to 2020, minority representation decreased at every advancing stage in surgical oncology training. Efforts to address barriers for URM applicants to CGSO fellowships are needed.