We have developed an efficient strategy for the production of stable β-palladium hydride (PdH0.43) nanocrystals with controllable shapes and remarkable stability. The as-synthesized PdH0.43 nanocrystals showed impressive stability in air at room temperature for over 10 months, which has enabled the investigation of their catalytic property for the first time. The prepared PdH0.43 nanocrystals served as highly efficient catalysts in the oxidation of methanol, showing higher activity than their Pd counterparts. These studies opened a door for further exploration of β-palladium hydride-based nanomaterials as a new class of promising catalytic materials and beyond.