Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Though biannual ultrasound surveillance with or without alpha-fetoprotein (AFP) testing is recommended for at-risk patients, its sensitivity for early-stage HCC detection is suboptimal. We therefore evaluated performance of a biomarker panel incorporating methylated DNA markers (MDMs) and proteins for early HCC detection in at-risk patients with chronic liver disease. Methods: In an international, multicenter, case-control study, blood specimens were collected from patients with HCC per AASLD criteria and controls matched for age and liver disease etiology. All patients had underlying cirrhosis or chronic HBV infection. Whole blood was collected in cell-free DNA stabilizing and serum-separation tubes and shipped to a central laboratory for processing. The levels of 5 MDMs, AFP, and AFP-L3 were assessed along with age and sex. We used 537 samples in a 5-fold validation for developing a LASSO regression algorithm to classify samples as HCC positive or negative. Model robustness was tested by perturbing the data in silico and analyzing results with the predictive algorithm. Algorithm performance was compared to AFP alone and the GALAD score (Gender, Age, AFP-L3, AFP, and DCP). Results: The study included 136 HCC cases (81 early-stage—BCLC stage 0/A) and 401 controls. With specificity set at 89%, we developed a model using sex, AFP, and 3 MDMs (HOXA1, TSPYL5, B3GALT6) with higher sensitivity (70%) for early-stage HCC compared to GALAD (54%) or AFP (31% at 20 ng/mL or 52% at ≥7.7 ng/mL) (Table). The AUC for the HCC marker panel was 0.91 (95% CI 0.89 – 0.94) compared to GALAD (0.88; 95% CI 0.85 – 0.91) or AFP (0.84; 95% CI 0.81 – 0.87). The panel performed similarly in viral (AUC = 0.94) and non-viral (AUC = 0.89) etiologies. Conclusions: The robust algorithm based on novel blood-based biomarkers presented here provides higher sensitivity for early-stage HCC compared to other available blood-based biomarkers and, therefore, could significantly impact HCC clinical management and patient outcomes. Further clinical studies to validate the algorithm are ongoing. Clinical trial information: NCT03628651.