Background/Objectives: Nonalcoholic fatty liver disease (NAFLD), also referred to as metabolic dysfunction-associated steatotic liver disease (MASLD), affects roughly one-quarter of the global population and represents a major public health concern. Despite its rising prevalence and potential for serious complications, NAFLD remains underrecognized and poorly understood in many communities. This study aimed to assess knowledge of NAFLD and its determinants among adults in the Northern Border Region of Saudi Arabia. Methods: A descriptive, population-based cross-sectional study was conducted using a previously validated online questionnaire adapted from published NAFLD awareness instruments, administered to adults residing in the Northern Border Region of Saudi Arabia. Data were analyzed using Python (statsmodels, version 0.14), and non-parametric tests, correlation analyses, and multivariable linear regression were used to examine NAFLD knowledge and its associated determinants. Results: A total of 1016 adults (mean age 34.7 ± 11.8 years) were included in the analysis. The mean NAFLD knowledge score was 14.6 ± 8.3 out of 30 (48.7% correct responses), with a median of 16 (interquartile range 8–21). Overall, 59.2% of participants had poor knowledge, 26.8% had moderate knowledge, and 14% had good knowledge. In bivariate analyses, educational level (χ² = 15.62, p < 0.001), family history of liver disease (p = 0.001), body weight category (p = 0.003), and smoking status (p = 0.007) were significantly associated with NAFLD knowledge. In multivariable linear regression, university education (B = 2.783, 95% CI 0.627–4.940, p = 0.011) was an independent positive predictor of higher knowledge scores. Current smoking (B = −1.857, 95% CI −3.477 to −0.237, p = 0.025), private-sector employment (B = −1.934, 95% CI −3.867 to −0.001, p = 0.050), and overweight status (B = −4.119, 95% CI −7.337 to −0.901, p = 0.012) were independently associated with lower knowledge scores. The final model explained 2.2% of the variance in knowledge (adjusted R² = 0.022). Conclusions: This study demonstrates generally low levels of NAFLD knowledge among adults in the Northern Border Region of Saudi Arabia, with only a minority achieving good knowledge scores. The findings underscore the need for targeted health promotion initiatives, educational interventions, and public campaigns to improve awareness of NAFLD and to support its prevention and management.