Li-rich antiperovskite (Li₂Fe)SO is a promising cathode material for Li-ion batteries due to its high specific capacity, low cost and toxicity. We present a sustainable and environmentally friendly approach for the green synthesis of Li-rich (Li₂Fe)SO using ball milling. This one-step process enables the preparation of a large quantity of phase-pure (Li₂Fe)SO using low-cost and non-toxic precursors, providing a viable alternative to the current solid-state synthetic method in terms of simplicity, laboratory safety and scalability. The obtained nearly spherical particles are in the micrometer range with a narrow size distribution. Additionally, we introduce a strategy to significantly reduce the ball milling time by increasing the ball-to-powder ratio, which is beneficial for energy saving. Post-heat treatment after ball-milling was found to be an effective strategy to control the internal structure, crystallinity, and morphology of the ball-milled (Li₂Fe)SO. Our results highlight the advantages of using ball milling in scaling up and controlling the structure and morphology of (Li₂Fe)SO cathode for tunable electrochemical properties. This sustainable synthesis approach has great potential to make an essential contribution to the development of low-cost and environmentally friendly Li-ion batteries.