• PtPdRuCoNi(111) identified as most promising HEA catalyst for HER with ΔGH* of −0.03 eV, outperforming Pt(111).
• Machine learning (XGBR) accelerates DFT screening with high accuracy (RMSE = 0.128 eV), reducing computational cost.
• Adsorption energies between −0.50 and −0.60 eV and d-band center of −1.85 eV indicate enhanced catalytic activity.
• Study demonstrates potential of HEAs for efficient and sustainable hydrogen production, addressing cost and scarcity of noble metals.