Background: Stigma towards individuals with obesity is a matter of global concern with several biopsychosocial outcomes. Obesity stigma from the general public keeps those with obesity to stay away from health care, employment, and educational facilities. The development of stereotypes due to weight stigma can limit opportunities and increase psychosocial distress among overweight or obese individuals. Objective: The aim of the study was to assess sociodemographic determinants of obesity stigma/ fat phobia of the general public. Methods: This descriptive cross-sectional study was done in Riyadh city of KSA. A representative sample of adult residents of both gender (n=374) of Riyadh city was selected at random. A validated and structured questionnaire was used to collect sociodemographic data. The obesity stigma of the respondents towards individuals with obesity was measured by using a Fat Phobia Scale (FPS). Data analysis was undertaken to examine sociodemographic variables' influence on the fatphobia score using chi-square analysis: percentages, Mann Whitney U test. Median, Inter Quartile Ranges (IQR), and frequency distribution were used to express the data. Results: Weight stigma of the mild form (FPS= 3.00 (2.79, 3.21) was observed among the general public. Females showed more obesity stigma than males. Sociodemographic variables such as age, gender, and marital status have no significant influence on fatphobia. Educational status significantly influences the FPS and fatphobia. Conclusions: The general public has mild fatphobia/weight stigma, which can be changed with higher education and health education.