In a digitalized world, accessing disease information through online platforms has become essential in influencing health-promoting behaviors among patients with heart failure. Patients must possess sufficient digital health literacy to obtain accurate and reliable information from digital platforms; however, there is no known data about the mediating role of digital health literacy in the relationship between health behaviors and symptom burden among persons with heart failure. To examine the relationship between digital health literacy, health behaviors, and symptom status (frequency, severity, and level of discomfort) in persons with heart failure and the mediating role of digital health literacy in the relationship between health behaviors and symptom status. This cross-sectional, correlational study was conducted between November 2023 and June 2024 with 250 persons diagnosed with heart failure. Data were collected using the Heart Failure Health Behavior Scale, e-Health Literacy Scale, and Heart Failure Symptom Status Scale. Pearson correlation analysis, linear regression, and hierarchical regression analysis with PROCESS Model 4 were used to analyze the continuous variables. Digital health literacy was positively but weakly correlated with health behavior and negatively correlated with symptom status. The mediation analysis revealed that part of the effect of health behaviors on symptom status was mediated by digital health literacy. Health behaviors directly affected symptom status and indirectly affected symptom status through digital health literacy. Strategies developed by nurses to enhance digital health literacy could play a critical role in improving the health of persons with heart failure by reducing symptom burden and promoting health behaviors. Research is needed on the influence of various predictors on symptom burden and assessing whether interventions to enhance digital health literacy can improve health outcomes among those with heart failure.