In this westernized culture, maintaining a healthy lifestyle has become a major health concern internationally. Health literacy is an emerging concept and requires effective measures and reform to improve the health status and health of individuals at both national and international levels, and has become one of the important determinants of individual health and healthcare service. This study aimed to assess health literacy among adults in Saudi Arabia. A cross-sectional study was conducted among a randomly selected population using a structured validated questionnaire over 4 months in 2021. The questionnaires designed for the study included 26 items divided into 5 domains assessed on a five-point Likert scale. Data were analyzed using IBM SPSS Statistics 26 (IBM Inc., Chicago, IL, USA) and IBM SPSS 26 (IBM Inc.). The mean score for reading, access to information, understanding, appraisal, and decision-making was 12.01 ± 4.37, 20.16 ± 7.17, 24.84 ± 8.37, 11.85 ± 4.90, and 36.94 ± 10.41 respectively. The mean scores of reading and understanding domains were found to have significant differences concerning gender ( P < .05). Additionally, participants’ age was significantly associated with the mean score of reading and decision-making ( P < .006 and P < .049). The findings reported a prevalence of inadequate HL in the population of Saudi Arabia was 54.4%, and the determinants associated with the scores of HL were age, gender, and education.