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The primary advantage of the high energy ball milling (HEBM) process is its ability to synthesize a homogeneous mixture with submicron (up to nanoscale) particle size. This approach is a viable process for particle size reduction and grain refinement of magnetic powders, which affects their domain structure and by extension the resulting magnetic properties. In this research, we designed a 9-ball milling experiment by keeping the rotational speed constant at 300rpm and varying the ball-to-powder ratio of 5:1, 8:1, and 10:1 for 6hrs, lOhrs, and 14hrs milling times. The strontium ferrite magnetic powders subjected to HEBM were analyzed for crystallite size and behavior via XRD, particle size reduction via SEM/ImageJ software/originLabPro, and magnetic performance via powder-based VSM measurement. The magnetic performance of the ball-milled strontium ferrite powders shows a good combination of appreciable increment in the S-values (a ratio of the remanence to saturation magnetization) and a considerable decline in coercivity (<10% decrease) at 6hrs of milling duration. The particle size obtained at 6hr-8:1BPR is 0.59 µm with about 44% reduction from the 1.05 µm particle size of the unmilled strontium ferrites, which is within the reported single-domain particle critical size (0.5 µm - 0.65 µm). The particle size reduction of 0.59 µm at 6hr-8: lBPR would be beneficial in enabling strong interfacial bonding when the ball­milled strontium ferrite powders are used in polymer-bonded magnets.