Context: Burnout is a psychological syndrome that results from prolonged exposure to stressful work activities and includes 3 dimensions: emotional exhaustion (EE), depersonalization (DP), and low sense of personal accomplishment (PA). Burnout is a widespread problem in numerous professions but is particularly high among medical students, residents, and early-career physicians compared with college graduates of similar age. However, minimal research has addressed burnout in osteopathic medical students. Objective: To assess levels of burnout in osteopathic medical students and to examine the relationship among burnout, perceived stress, sleep quality, and smartphone use. Methods: This study used a cross-sectional study design and an anonymous, electronic questionnaire service to administer the Maslach Burnout Inventory, the Perceived Stress Scale-4, the Pittsburgh Sleep Quality index, and the Smartphone Addiction Scale Short Version. Results: A total of 385 participants (mean [SD] age, 25 [2.4] years; 208 [54.0%] women; 286 [74.3%] white; 138 [35.8%] second-year osteopathic medical students [OMSs]) completed the survey. Of the 385 participants, 9 (2.3%) reported high EE, 67 (17.4) reported high DP, and 310 (80.5) reported a high level of low PA. When comparing dimensions of burnout by gender, only levels of PA differed by gender, with men reporting higher levels of burnout compared with women (χ 1 2 =5.2, P=.022). Further, levels of DP differed by year in medical school (χ 2 =17.3, P=.008), with posthoc comparisons showing differences between OMS I and OMS III (F=4.530, df=3, P=.004). Linear regression models showed that higher perceived stress (standardized β=0.5, P<.001), poorer sleep quality (standardized β=0.2, P=.001), and higher smartphone addiction scores (standardized β=0.1, P<.001) were associated with higher EE. Similarly, higher perceived stress (standardized β=0.2, P<.001), poorer sleep quality (standardized β=0.2, P=.001), and higher smartphone addiction scores (standardized β=0.2, P=.001) were associated with higher DP. Only higher perceived stress was associated with higher levels of low PA (standardized β=−0.4, P<.001). Conclusions: These findings suggest independent associations with EE, DP, perceived stress, sleep quality, and smartphone use. Additional research with a larger, more diverse sample is needed to confirm these findings. If confirmed, wellness interventions can be designed to target 2 modifiable factors: sleep quality and smartphone use.