Purpose: Harmful alcohol use among University students is a problem throughout the world. However, little is known about alcohol use disorders among JFD university students in Ethiopia. Therefore, this study aimed to assess the prevalence and associated factors of alcohol use disorder (AUD) among Jimma University undergraduate students. Methods: Institution-based cross-sectional study was conducted among Jimma university students. Data were collected from 741 sampled students who were selected through a multistage stratified sampling technique. Alcohol Use Disorder Identification Test (AUDIT), Oslo 3 items social support scale (OSS-3), and Kessler-6 (K6) tools were used to assess alcohol use disorders, social support, and psychological distress, respectively. Data were analyzed through SPSS version 20.0. Bivariate and multivariate logistic regression analyses were conducted and adjusted odds ratio (AOR) at a 95% confidence interval (CI) was used to determine the independently associated factors of AUD. Results: The overall prevalence of AUD among Jimma University undergraduate students was 26.5%. There was a positive and independent association between AUDs and being single AOR= 1.98, 95% CI [1.21, 3.22], having a history of mental illness AOR= 1.98, 95% CI [1.04, 3.75], having a history of suicidal attempt AOR= 3.63, 95% CI [1.18, 11.11], smoking cigarette AOR= 5.04, 95% CI [2.02, 12.57], having peer pressure to drink alcohol AOR= 2.72, 95% CI [1.76, 4.19] and presence of mental distress AOR= 2.81, 95% CI [1.83, 4.32]. Conclusion: The findings of this study showed that the prevalence of AUD was high in the sampled undergraduate students of Jimma University. AUD was positively associated with mental, substance, and behavioral risk factors. Therefore, concerted actions needed to emplace to increase the student's awareness of the effect of harmful alcohol use. Moreover, it is recommended that further studies need to be conducted to develop strategies for evidence-based interventions.