Sleep duration is associated to various health impairments, while its comprehensive association with tinnitus is rarely investigated. The current study aimed to explore the relationship between sleep duration and tinnitus incidence, and to determine the optimal sleep duration relating to the lowest tinnitus risk. Data of participants from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2012 and 2015 to 2018 were retrieved. A total of 13,871 participants were eligible and included in the analysis. Generally, sleep duration was lower in participants with tinnitus compared to those without (7.15±1.76 vs 7.30±1.51 h, P<0.001). After adjustment by demographics, lifestyle, and chronic diseases, a U-shaped relationship between sleep duration and tinnitus incidence was observed, with the inflection point at 8.5 h. Interestingly, in participants with sleep duration <8.5 h, sleep duration exhibited an independent negative correlation with tinnitus risk [OR=0.88 (95%CI: 0.84-0.93), P<0.001], while in participants with sleep duration ≥8.5 h, sleep duration had an independent positive association with tinnitus risk [OR=1.16 (95%CI: 1.04-1.28), P=0.006]. In conclusion, a U-shaped relationship was found between sleep duration and tinnitus incidence, with a sleep duration of about 8.5 h being associated with the lowest tinnitus risk.