Mental illnesses or psychiatric disorders are very common worldwide although, a lot of patients might go undiagnosed and untreated due to the stigma towards mental illness that drives the patients away from seeking medical help. Aim of the work: this study aimed to evaluate the background and attitude of the general population throughout Saudi Arabia about mental illnesses. Method: a cross sectional study analyzed data from 5850 participants aged 18 and up. From all 13 districts of Saudi Arabia. The data were collected using self-administered anonymous electronically distributed questionnaire, between the months of April- May of 2017. The data were analyzed using the statistical analysis system (SAS version 9.1; SAS Institute, Cary, NC). Crude associations were assessed using Pearson Chi -square test. P value of less than 0.05 was used to indicate statistically significant differences. Result: the mean age of the studied subjects was 28.7 ± 9.8 years. Subject's background about the general nature of psychiatric disorders was high and exceeding 90% regarding the nature of psychiatric disorders and whether they were similar or not, a very low percent (7%) showed that psychiatric patients cannot socially adapt, while 96.9% believed that psychiatric patients were considered insane. (52%) believed psychiatrists are affected by their patients on long term exposure. Conclusion: he background of Saudi population regarding mental illnesses is considered fair, the attitude towards psychiatric patients need further education to minimize the stigma towards them.