Background: Sleep deprivation impacts physical and emotional health, particularly among incarcerated individuals. Ethiopian prisoners often experience poor sleep quality, which impacts their health and rehabilitation. However, more research is needed, especially in Jimma zone. Objectives: The aim of this study is to assess the magnitude of poor sleep quality and associated factors among incarcerated individuals in Jimma Correctional Facility, Jimma, Oromia, and Southwest Ethiopia in 2024. Methods: A cross-sectional research design was employed from April 1 to June 30. The simple random sampling method was used to select 300 study participants. Data were collected by trained data collectors using pretested and structured questionnaires. Standardized tools, such as the Pittsburgh Sleep Quality Index, PHQ-9, GAD-7, PSS-10, Sleep Hygiene Index, and Oslo-3 Item Scales, were used to collect quantitative data. The data were entered into Epi data version 4.6 and then exported to SPSS version 26 for analysis. Bivariate and multivariate logistic regression analysis was applied to assess associations between dependent and independent variables. The odds ratio with a 95% confidence interval was used to determine the strength of associations between dependent and independent variables. P-values less than 0.05 were considered statistically significant. Results were summarized and presented through text, tables, and figures. Result: Response rate for this study was 100%. Among the 300 participants, the prevalence of poor sleep quality was 72% (95%CI: 67.3-77.0) and it was found to be statistically associated with religion (AOR = 17.39, 95% CI (4.36, 69.31)), drinking tea and coffee close to bedtime (AOR = 2.39, 95% CI (1.140, 5.016)), depression (AOR = 4.195, 95% CI (1.956, 9.00)), and anxiety (AOR = 2.39, 95% CI (1.151, 5.002)). Conclusion and Recommendation: Poor sleep quality among inmates at Jimma correctional facility was associated with factors like sex, religion, crime type, and khat use. This highlights the need for routine screening and management for sleep quality, as inmate health is negatively impacted by inmate care and sleep deprivation.