Background/Objectives: Hepatitis B virus (HBV) remains a significant diagnostic and public health challenge worldwide. Despite widespread vaccination, underdiagnosis persists among adults in Saudi Arabia. This study estimated HBV prevalence and identified sociodemographic, clinical, and behavioral predictors relevant to improving targeted diagnostic screening. Methods: A cross-sectional study of 1196 Saudi adults aged ≥18 years was conducted between September 2024 and February 2025 using a structured questionnaire. Data on demographics, clinical history, and behavioral exposures were analyzed using chi-square tests and multivariate logistic regression to identify independent determinants of HBV infection. Results: The study included 1196 adults (60.0% female, mean age 31 ± 12 years). HBV prevalence was 2.0% (95% CI: 1.3–3.0%). Independent predictors included divorced/widowed marital status (OR = 3.99, p = 0.023), diabetes mellitus (OR = 3.59, p = 0.039), family history of HBV (OR = 2.55, p < 0.001), and massage exposure (OR = 3.99, p = 0.025). No significant associations were found with gender, education, or transfusion history. Conclusions: HBV infection persists among high-risk Saudi adults despite immunization success. Integrating HBV testing into diabetes care, premarital and household screening, and regulation of personal care services may enhance early diagnosis and advance national elimination goals.

Background and Objectives: Adult uptake of hepatitis B virus (HBV) vaccination and screening in Saudi Arabia is poorly characterized. This study estimated both behaviors among working-age adults without a previous HBV diagnosis and identified their independent determinants. Methods: A cross-sectional online survey was conducted between November 2024 and April 2025. After exclusion of participants with a previous HBV diagnosis, 1243 adults aged 18 to 64 years were analyzed. Multivariable logistic regression estimated adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: Overall, 324 participants (26.1%) reported HBV vaccination and 169 (13.6%) reported screening, whereas 873 (70.2%) reported neither. Good knowledge was associated with vaccination (aOR = 4.77; 95% CI: 3.48–6.55) and screening (aOR = 4.59; 95% CI: 2.97–7.09). Healthcare work (aOR = 5.24 and 3.55) and educational program participation (aOR = 2.77 and 3.38) were also associated with both outcomes. A family history of HBV was associated with vaccination only (aOR = 2.49; 95% CI: 1.49–4.16). Vaccination odds were lower among men (aOR = 0.69; 95% CI: 0.49–0.96) and declined with age (aOR = 0.959 per year). Sickle cell disease was associated with screening (aOR = 3.88; 95% CI: 1.38–10.90). Attitude was not associated with either outcome. Conclusions: HBV vaccination and screening uptake was low in this sample and was concentrated among healthcare workers and adults with good knowledge or previous health education. Building on existing premarital, antenatal, and occupational screening, routine offers of testing and vaccination in primary care could reach groups that current services miss, particularly older adults, men, and household contacts of people with HBV.