<p>This paper presents a potentially lower-carbon high-entropy alloy (HEA) powder fabrication route that uses metal oxide powders as raw feedstock and employs hydrogen reduction to produce only water vapor as a byproduct. Conventional fabrication routes for HEA powders such as casting, gas atomization, and mechanical alloying rely on metallic raw materials whose production generates considerable CO₂ emissions during melting, atomization, and powder synthesis. These carbon-intensive processes highlight the need for alternative sustainable feedstocks. Chromium, which is a corrosion-resistant and oxidation-stable material to be suitable for extreme environments such as high temperatures and chemically aggressive conditions, was incorporated into HEA. However, the hydrogen reduction of Cr₂O₃ typically requires high temperatures, which is a major challenge to oxide-based HEA fabrication. This study lowers the processing temperature by forming a solid solution of oxide powders through high-energy milling, promoting oxide solid-solution formation. Milling refines the oxide powders to the nanoscale, improving compositional homogeneity and reducing the activation energy required for Cr₂O₃ reduction, thereby enabling partial hydrogen reduction at a significantly lower temperature of 1,000&#xa0;°C. The milled powders were spray dried into spherical agglomerates and hydrogen-reduced, which achieves a sphericity of 0.974. After sintering, the hydrogen-reduced sample exhibited higher hardness (3.23 ± 0.28 GPa) and more uniform distribution than that of the gas-atomized counterpart (1.94 ± 0.40 GPa). The sample sintered from the hydrogen-reduced powder exhibited a more uniform hardness distribution than that of the sample sintered from the gas-atomized powder with lower porosity.</p> Graphical Abstract <p></p>