Objective: To examine the association of sleep duration, physical activity, and their joint effects on depressive and anxiety symptoms among college students, and to provide evidence for the prevention and intervention of emotional symptoms in the population. Methods: From October to December 2023, a total of 7 684 college students aged 18-22 years, who were selected from nine universities in Hubei, Jiangxi, and Anhui provinces by using convenience sampling, underwent questionnaire surveys and physical examinations. Chi-square test and Logistic regression model were used to analyze the associations of meeting sleep duration and moderate to vigorous physical activity (MVPA) recommendations, as well as their joint effects, with depressive and anxiety symptoms. Results: The prevalence rates of depressive and anxiety symptoms were 25.78% and 35.59%, respectively. The prevalence rates of both depressive and anxiety symptoms differed significantly across sleep duration and physical activity groups ( χ 2= 9.32 -127.01, all P <0.01). Logistic regression analyses showed that insufficient sleep duration and failure to meet the physical activity recommendation were associated with higher odds of depressive symptoms ( OR =1.67, 1.20) and anxiety symptoms ( OR = 1.74 , 1.21 ) (all P <0.01). Further joint effects analyses showed that the combination of insufficient sleep and insufficient MVPA and that of insufficient sleep and sufficient MVPA were associated with higher odds of depressive symptoms ( OR =1.94, 1.38 ) and anxiety symptoms ( OR =2.09, 1.59) (all P <0.05). The combination of sufficient sleep and insufficient MVPA was also associated with higher odds of anxiety symptoms ( OR =1.16, P <0.05). Conclusions Sleep duration, physical activity, and their joint effects are associated with depressive and anxiety symptoms among college students. Joint interventions targeting both sleep and physical activity should be emphasized to reduce the risk of emotional symptoms.