This study explored the hypothesis that social determinants of health (SDOH), including racial and economic differences, may impact orthopaedic trauma outcomes in patients undergoing open reduction and internal fixation (ORIF) of humeral shaft fractures. Design: Retrospective. Single, academic, tertiary Level-I trauma center. Adults with midshaft humerus fractures (AO/OTA 12) treated operatively with plate fixation from 05/2011 to 05/2021 with a minimum follow-up of nine months. Radiographic fracture healing, complication rates, and patient-reported outcomes were investigated. SDOH were assessed using the Area Deprivation Index (ADI). Demographics, complications rates, and patient-reported clinical outcomes were compared between the first and fourth ADI quartiles. 196 patients fit the study criteria. The average age of the cohort was 47 years with 50 women (51%). Comparisons of the least deprived quartile (n=49) to the most deprived quartile (n=49) yielded similar sex distribution (59% vs 43% female, p=0.15), fewer non-white patients (8% vs 51%, p<0.01), older average age (51 years vs 43 years, p=0.05), similar BMI (30.5 vs. 31.8, p=0.45), and higher Charlson Comorbidity Index (CCI) (2.2 vs.1.1, p=0.03). While nonunion rates were similar (p=0.20) between groups, the most deprived quartile had 2.3 times greater odds of post-operative complications (p=0.04). Patients in the most deprived group exhibited higher PROMIS Pain Interference (PI) scores (p<0.01) and PROMIS Depression (D) scores (p=0.01), with lower PROMIS Physical Function (PF) scores (p<0.01) at 6-month follow-up than the least depriver cohort. The most deprived cohort had three times higher odds of missing scheduled appointments within the first post-operative year (p<0.01), resulting in a significantly higher no-show rate (p<0.01) than the least deprived cohort. Regression analysis including several demographic and injury factors identified that ADI was significantly associated with the occurrence of any missed appointments (p<0.01), no-show rates (p=0.04), and experiencing one of the following post-operative complications during recovery: Nonunion, radial nerve injury, or dysfunction (p=0.03). Patients experiencing greater resource deprivation faced increased odds of complications, missed appointments, and poorer PROMIS outcomes following humeral shaft fracture fixation, emphasizing that baseline socioeconomic disparities predict unfavorable post-operative outcomes even given favorable baseline health status according to the CCI score. Level III. See Instructions for Authors for a complete description of levels of evidence.