Abstract Developing highly active and CO‐resistant Ru‐based catalysts for the alkaline hydrogen oxidation reaction (HOR) can advance the large‐scale application of alkaline hydrogen fuel cells but remains a huge challenge. Herein, a pure phase W 2 C supported Ru cluster catalyst (Ru/W 2 C) is successfully synthesized through a one‐step carburization method. It is found that the charge transfer from W 2 C to the strongly anchored Ru clusters forms the electron‐rich Ru δ− sites and electron‐deficient W δ+ sites, which significantly weakens the adsorption strength of * H and * CO, strengthens the binding of * OH and improves the water connectivity in the electric double layer. The Ru/W 2 C catalyst shows superior mass activity (2163 mA mg PGM −1 ) in alkaline HOR, which is 12.52 and 20.62 times higher than that for Pt/C and Ru/C, respectively. Owing to the weak adsorption and fast removal rate of CO, the Ru/W 2 C exhibits outstanding CO tolerance, with 88% of the initial activity being retained in the durability test, whereas the Ru/C and Pt/C suffer from severe deactivation. These findings may guide the design of advanced alkaline HOR catalysts based on the pure phase tungsten carbide.