Background: Depression is a significant public health problem among college students and may have an adverse impact on academic function, social activity and life satisfaction. Academic stress, lifestyle changes, financial concerns and social issues are the major factors that contribute to higher frequency of depressive symptoms among undergraduate students. Objective: This study aimed to calculate the prevalence of depressive symptoms among undergraduate students in Jazan University and find out the factors that were associated with depression in terms of the sociodemographic characteristics, academic activities, and lifestyle. Methods: Cross sectional analytical study was carried out on undergraduate students of Jazan University. The data were gathered by a structured questionnaire that included sociodemographic parameters, academic-related, lifestyle behaviors and the Patient Health Questionnaire-9 (PHQ-9) for depressive symptoms assessment. The PHQ-9 scores were derived and classified by the severity of depressive symptoms. SPSS was used to analyze the data, chi square and t-test were applied. Results: The total number of undergraduate students who participated in the study were 500. Results showed that many of the participants had a high level of depressive symptoms on the PHQ-9 assessment. Several factors such as gender (χ² = 24.621, p<0.001), age group (χ² = 27.905, p<0.001), marital status (χ² = 16.341, p = 0.001), family income (χ² = 49.031, p<0.001), parental education, chronic disease and previous depression history were found to have significant associations with depressive symptoms.   Conclusion: The study highlights the fact that depression symptoms are a significant mental health problem among Jazan University undergraduate students. Academic stress, socioeconomic factors and certain health-related variables were all significant factors associated with depressive symptoms. The results indicated that more attention should be paid to conducting early screening, mental health awareness programmes, counselling and prevention in university environments to promote the psychological health of students.