This work presents Cobalt-Boride (Co–B) as a non-noble, efficient and robust electrocatalyst for Hydrogen Evolution Reaction (HER) active in aqueous solution of wide pH values. In neutral solution, amorphous Co–B nanoparticles (30–50 nm size) generate high current density (10 mA/cm²) at low overpotential (250 mV) with Tafel slope of 75 mV/dec following Volmer–Heyrovsky reaction mechanism. Highly active Co surface sites created by electronic transfer from B to Co (as inferred from XPS analysis and supported by theoretical calculations) are responsible for this significant HER activity in wide range of pH (4–9) values. Stability and reusability tests also demonstrate the robust nature of the catalyst.