IMPORTANCE Previous studies have shown high rates of mistreatment among US general surgery residents, leading to poor well-being. Lesbian, gay, bisexual, transgender, queer, and other sexual and gender minority (LGBTQ+) residents represent a high-risk group for mistreatment; however, their experience in general surgery programs is largely unexplored. OBJECTIVE To determine the national prevalence of mistreatment and poor well-being for LGBTQ+ surgery residents compared with their non-LGBTQ+ peers. DESIGN, SETTING, AND PARTICIPANTS A voluntary, anonymous survey adapting validated survey instruments was administered to all clinically active general surgery residents training in Accreditation Council for Graduate Medical Education-accredited general surgery programs following the 2019 American Board of Surgery In-Training Examination.MAIN OUTCOMES AND MEASURES Self-reported mistreatment, sources of mistreatment, perceptions of learning environment, career satisfaction, burnout, thoughts of attrition, and suicidality. The associations between LGBTQ+ status and (1) mistreatment, (2) burnout, (3) thoughts of attrition, and (4) suicidality were examined using multivariable regression models, accounting for interactions between gender and LGBTQ+ identity.RESULTS A total of 6956 clinically active residents completed the survey (85.6% response rate). Of 6381 respondents included in this analysis, 305 respondents (4.8%) identified as LGBTQ+ and 6076 (95.2%) as non-LGBTQ+. Discrimination was reported among 161 LGBTQ+ respondents (59.2%) vs 2187 non-LGBTQ+ respondents (42.3%; P < .001); sexual harassment, 131 (47.5%) vs 1551 (29.3%; P < .001); and bullying, 220 (74.8%) vs 3730 (66.9%; P = .005); attending surgeons were the most common overall source. Compared with non-LGBTQ+ men, LGBTQ+ residents were more likely to report discrimination (men: odds ratio [