Facile deposition of transition metal boride (TMB) with high‐boron content as highly efficient hydrogen evolution reaction (HER) electrocatalyst has been realized by a facile one‐step electroless‐plating (EP) method. Boron content of the TMB catalyst shows an appreciable impact on its intrinsic HER activity. NiB/NF electrode with thin amorphous nickel boride (NiB) deposition on nickel foam (NF) required overpotential of only 41.2 mV to deliver a current density of 10 mA cm−2 for HER in 1.0 M KOH alkaline electrolyte. Meanwhile, this kind of electrode also shows satisfied stability which can work at large current density of 1000 mA cm−2 for over 72 h without performance degradation. The advance on the TMB electrode may pave a way to the development of practical electrodes for water splitting.