Calcium is an essential skeletal mineral, and calcium deficiency has a negative impact on bone health. We conducted an online questionnaire to assess the intake and knowledge among the Saudi population. The survey included 950 participants, with 51.1% demonstrating poor knowledge of calcium sources and a mean intake lower than the recommended level. INTRODUCTION: Calcium is an essential mineral and one of the most prevalent in the body. Chronic insufficient calcium intake increases the risk of osteopenia, osteoporosis, and bone fracture. PURPOSE: This study aimed to assess the Saudi population's calcium intake and knowledge of calcium sources as well as to identify factors associated with inadequate calcium intake. METHODS: This cross-sectional study was conducted across Saudi Arabia using an online questionnaire distributed randomly through social media channels. The questionnaire was a validated tool that was previously developed and used by the original author to assess knowledge of calcium food sources and estimate calcium intake in the Saudi population. If an individual answered more than 11 questions correctly, calcium knowledge was considered adequate. Calcium intake was considered sufficient or insufficient based on the recommended dietary allowance (RDA) of 1000 mg/day. RESULTS: The survey included male and female Saudi citizens and residents aged 14 years or older. A total of 950 respondents aged 9-70 completed the questionnaire. A total of 62.9% of the respondents were 26-50 years old. Of the participants, 64.2% were female, 71.7% were married, and 61.9% had a diploma or a bachelor's degree. Of these, 63.8% were from the central region, and 97.6% were from Saudi Arabia. For those aged 9-18, the average calcium consumption was 577 mg/day, whereas it was 479 mg/day for those aged 19-50. The average intake was 479 mg/day for males aged 51-70 (EAR = 1000 mg/day) and 438 mg/day for females (EAR = 1200 mg/day). These calcium consumption values were significantly lower than the estimated average requirement (EAR) and RDA (p < 0.01). Correct response rates for the 19 calcium intake knowledge items ranged from 23.4 to 94.7%. Among the participants, 48.9% had significant calcium intake knowledge, as indicated by a score of > 11 out of 19 correct responses. Age, sex, marital status, educational attainment, and residence were significantly correlated with adequate knowledge of calcium. Demographic characteristics such as age, marital status, and residence were associated with sufficient calcium intake in the study. CONCLUSION: The study findings revealed that a significant proportion (51.1%) of participants demonstrated inadequate knowledge regarding calcium food sources. Additionally, the mean calcium intake was found to be lower than the RDA of 1300 mg/day for males and females 14-18 years old and 1000 mg/day for males and females 19-50 years old and males 51-70 years old; however, the RDA for females 51-70 years old is 1200 mg/day, suggesting an urgent need for interventions aimed at enhancing both calcium knowledge and intake.