Introduction: In Saudi Arabia, 34% of Saudis have been diagnosed with a mental health illness at some point in their lives, with depression making up to 6% of the population. Teachers' mental health is a major problem across the world and has an impact on their students. This study is an attempt to investigate the prevalence of depression and its severity and associated sociodemographic and occupational risk factors among government primary school teachers in Dammam, Khobar, and Qatif.Methods: This is a cross-sectional study. The research tool used to conduct this study is an electronically administered Arabic-language questionnaire distributed randomly to all government primary school teachers in Dammam, Khobar, and Qatif. The numbers of participating teachers are 358,242 males and 116 females.Results: By using the Patient Health Questionnaire 9 (PHQ9) scale, it was found that 36.6% suffer from mild depression, 30.4% suffer from moderate to moderately severe depression, and 11.2% suffer from severe depression. The obtained results indicated that there is an association between the variable of the prevalence of depression and some sociodemographic factors such as physical or psychosocial abuse, and the occupational characteristic variables such as teaching more than three or more subjects and bad relationship with the school administration.Conclusion: More studies are needed to address the mental health issues among school teachers in Saudi Arabia.